I agree with Babak's answer. Try upgrading your underwear first. Don't wear the R1 or R2 as your base-layer and go for thicker outer layers, first try the Capilene 3 or 4 (or wool equivalents if you can afford it). I go snowshoeing in Capiline 4 + R2 + shell and I'll take the shell off if i'm too hot and it's not windy.

oh yeah R2's warmer...the R1 isnt much of a jacket but more of a layering piece, this is more of a fleese jacketIm in the same boat but want something warmer than the R2 which is what I currently use. I want to go to 3 layers instead of 4. I was just in NH skiing and found that it's tough to get away with less than 4 layers including the shell. I did try on a ARCteryx HERCULES which i think would be perfect. Warm long underwear, the Hercules, and the shell may help. Otherwise, currently im wearing thin long underwear, Cap 3, R2, shell which also works well.In skiing in anything from -10 to 20 F, I wear a baselayer (usually Wool 2 or 3), R1 (preferably Hoody) R2 and a shell and I stay perfectly comfy. The wool creates a microclimate around your body, and the R1 allows for prime heat exertion while the R2 breathes and retains heat like its nobody's business. The Shell is to keep the wind and elements out.