davidallenxyz
Regular
I have some Vaude gaiters/overshoes that I use on normal shoes. They are not thermal, but I have yet to feel the need for thermal footwear on a UK commute.
If some has found overboots that keep you totally dry in even heavy rain. Please let me know.
I got a pair of Ridge overshoes from Halfords for a tenner, and they fit over trainers fine. However, I haven't used them yet as the next week Aldi were doing waterproof lightweight walking boots, and I have been wearing those for the commute. I wouldn't take them up Snowdon, but on the bike they are warm and dry, and high enough to fit under the waterproof trousers so no water running into them. I had to take the toeclips off, though. No way would they fit.