I haven't tried a compression shirt as a winter base layer yet. I use that kind of shirt alone for temps in the 60's and alone under a nylon windbreaker for temps in the 50's and 40's, all depending on wind speed and direction, of course. When it gets colder than that, I consider switching to a merino wool midweight base layer. Colder still and I will use a loose poly shirt over the wool.

Two things I have learned this winter (my first winter commuting by bicycle):

- Everybody here on BF has a different preference, but I can learn from them all (and have)
- I bought one of several different kinds of shirts & pants and tried them out on my commutes and found what worked for me through (pre-educated somewhat by research ahead of time) trial and error

Good luck, I hope you find what works for you. If you find a good combo that works for you, post it up so we can learn and consider it.