I can't handle riding on a trainer. I got one, took it back and got some good winter gear instead. It need not cost you anything, since layering is really the way to go regardless. I always have cold hands and like mittens so I splurged on some lobster gloves and a helmet-friendly hat.

I am getting ready for a touring trip too (in Dec.) and find that 30 degrees and windy is a lot less painful than mind-numbing going-nowhere exercise indoors. But I get bored easily, and while it snows here it definitely doesn't get to minus 30!

Is your trip self-supported? I am feeling confident with my ability to put in a good number of miles each day but my big worry was doing that on a fully-loaded bike. I've been taking my bike to the grocery store, recycling center, etc. to work on that aspect, the store is a good workout when you are eating as much as I am!

I read that you can either start 'fit or fat' on trips like these, though, and in the end you will emerge fit regardless, you just have to give your body time to adapt to what you are asking it to do, either way, listen to pain, give yourself rest days and most of all enjoy it!

Anne