I might not be able to use a warm water bottle in it, as I am going to use it for camping in the Arctid (Svalbard). But I read some reviews that this wasn´t the best bag for high altitude camping anyway, so I just have to keep on looking for a good bag...

Are you asking if the temperature rating for this bag is different for women than for men? If so, the answer is no - temperature ratings are not gender-specific. However, there are many women-specific bags which are shorter and shaped differently. The goal is to minimize the volume of air that your body has to warm up inside the sleeping bag. I'm noticing that the regular length for this bag is 78 inches/194 cm which is typically a long length (the mountain hardwear website shows the same information). If you are shorter, you might consider other sleeping bags which are typically offered in 66 inches (5 foot 6 inches) and 72 inch (6 foot lengths). The additional advantage to getting a close-fitting sleeping bag besides thermal efficiency is that the bag will pack down smaller in your backpack.

Note that for cold weather sleeping bags, you might want a little extra length to allow for a water bottle with hot water to be kept down at your feet; its a pretty common mountaineering/winter camping trip to help warm up.

Synthetics for damp conditions, down for dry conditions. High altitude and cold climates are typically drier, so down is preferable. Down bags also last longer because synthetic fills (like thermic micro) degrade faster.

As far as staying warm while sleeping in the Rockies: the sleeping bag is only one part of your sleep system. Your sleeping pad is every bit as important as the bag you're in. Closed cell foam pads are cheap, lightweight, waterproof, versatile (can be used as splints, seats, emergency sleds, etc.) warm, and indestructible but they are bulky and not very well padded (check out a ridgerest). Insulated air mattresses are more comforatble, more expensive, pack down smaller, can leak/rip which makes them useless, are typically heavier, and require more care (I use the downmat 9).

Clothing is equally important. Companies rate their bags based on different assumptions about what the sleeper is wearing.

Colorado is generally a lot "drier" of snow than other places. Generally you need to manage your internal moisture more there than exterior moisture. Don't go to bed with too much clothing or you'll just sweat and wake up hours later moist and freezing. And if you don't need to don't curl up in your bag totally zipped up with the hood cinched tight.
Did you build your snowcave correctly? It shouldn't be that cold inside, the sleeping area should be a bit above the entrance to get the full protection of one.

If you are hiking a bit to camp I'd get a down bag. If you are camping by the road or in your backyard go with a cheaper and bulkier synthetic.

When looking at the temperature ratings for sleeping bags you need to keep in mind that there is no standard that defines what a 0 degree bag is vs a -10 degree bag vs -20, etc.... There are plenty of reasons for this, but one thing for sure is that different people need different amounts of insulation to sleep comfortably at different temperatures - there's lots of variables at play here. As for the difference between synthetic and down bags, I think the accurate statement is that if you have a down bag and a synthetic bag that both weigh the same amount, the down bag will be warmer and pack down smaller than the synthetic bag. It is certainly possible to make synthetic bags that are warm down to the same temperature rating as the warmest down bags, but they will be heavy and bulky.

As you point out, down bags do have their drawbacks because, once wet, down loses its loft and no longer provides any warmth. Its necessary to take many precautions when using down sleeping bags (such as lining the stuff sack with a trash compactor bag to keep water out). Honestly, I've never slept in a snowcave, so I'm not sure how safe it is to use a down bag in this situation. There are down bags though that have waterproof shells - Mountain Hardwear makes a few; other companies use materials such as GoreWindstopper or Epic which are highly water resistant.

ice climbing and mountaineering trips on the cheap leave you sleeping in the car A LOT. my advice, for an in car sleeping bag, is to go with a synthetic, not a down. It's cheaper, better when wet, and you're not concerned with weight or bulk. Unlike tents, cars don't breathe. In cold weather you'll wake up with a layer of frost over everything in the car which will get things wet when you turn the heat on. This happens even in dry climates because of exhaled moisture. As long as it's not dumping snow, you can leave the windows open (1 person in the car = 4 windows each 1/4 down; 2 people in the car = 4 windows 1/2 down) and you should be good.

A -30 down bag will cost you $600 or more. If you are using it in the car, the extra weight and space does not matter. I would not carry this bag. If you are just going to use it in a car, then get it. You can't beat the price.

why this and not down filled? i want the warmest thing for super cold camping

I don't think you would need something quite like this, since you are out of the wind and are off the ground, but you will be hard pressed to find a bag suited for colder conditions. A -30F bag is about as warm as they come. You might want to consider a down bag, since they are warmer, and take up less space, which might be a plus on a longer trip. You won't be getting it too wet in the car, so down seems like a better option.

12L or the large size will fit but a bit tight. 16L or the extra large size will give you a little more room for a few extra things to be compressed.

Thanks for the catch George. A note has been sent to the powers that be to shift it over to the synthetic bags... sorry.