I have some northwave celicius boots and they are freezing. I think they do an insulated version now but I was not that impressed with them. They also weren’t that waterproof after a bit.
I now use the Shimano walking boot SPD shoe. They are great, warm, comfy and dry. Although water does get in the tops like any shoe. When they do get a soaking they take days to dry out.
I like the rubber glove idea. I was meaning to get round to buying some dry suit cuffs to do the same idea.
EDIT: Meant to say, surely the “cheapest” method would be to buy some good value comfy normal shoes and glue a neoprene overshoe onto the rand. Common practice for mountaineering boots and gaiters.