I recommend get the proper cycling shoes and clipless pedals, trainer shoes are just a bad idea. Cycling shoes are the best, do not flex, put more power in the pedalling. Clipless is likewise, try them on a minimum setting. Shimano M540 are very good, Also overshoes are a godsend, but never designed for trainer's.
I do a lot of cycling touring and used to have clips, but have converted to clipless and never looked back. Yes there do getting some used to, but once you have the technique. It's like the brain telling to you stop, it's automatic. Same with clipless, the brain will tell you unclip before a junction or traffic lights.
Also if you do come off the bike
the pedals will auto release.
I go to work on my bike and use Army boots in the winter month.