I'm in the exact same boat. We leave tonight & we had a BFP yesterday (4 weeks & can't take the smiles off our faces). i am a beginner/medium skiier.
We have done a lot of reading of MN posts on this matter. DH has been worried about this since we started trying.
Seems pretty consistent advice from what I've read. Docs say its fine because its so protected. You would have to have an almighty traumatic accident to cause a MC from skiing from what i can gather.
I think it more about listening to your body. I don't know if you have skiied bf ( & you are swapping to snowboarding) or if totally new to skiing and snowboarding but I always find skiing so exhausting (and I am reasonably fit person).
Snowboarding from what I can gather is a real pain in the behind (literally and figuratively). I've known good skiiers who have really struggled with their 1st of snowboarding becuase of the amount of time spend on their bottoms.
So, I think if you are a total newbie, then maybe opt for skiing instead (don't buy the whole week pass and take the hit on booking a day at a time) or the total relaxation break option (kindle, mags, spa). If you have a bit of skiing experience, stick with skiing or if you are an experienced skiier and are desparate to try snowboarding, then again, don't try for the whole week (but a few days and then buy days here and there if you feel up to).
Now apres' ski is another matter. If anyone has any good excuses for not drinking when holidaying with a big group. I would almost always drink socially so it is going to be obvious when I say no thanks. The old "Im on antibiotics one" seems a little too obivous.