I'm with you!
I commute all winter, but will rarely even touch my tri bike until spring.
Yes, I could put it on the trainer. Yes, I probably should. Yes, I set a ridiculously high number for the challenge, and no, I won't reach it.

I'm with Beth: riding inside feels like exercise. I'd rather be having fun. And even tho my commute is only 3 miles each way- at least I have fun for those 30 minutes a day. Can't say I'd be having fun on the trainer for 30 minutes (heck, I wouldn't be having fun for 5 minutes on the trainer). I thought the indoor challenge would motivate me. I was wrong.