I've been thinking about investing in a pair of higher quality boots myself…I currently just use the insulated big rubber boots by Baffin, don't know if they're there the same as the tundras previously mentioned. They're plenty warm for me, they're deliberately a size bigger than I'd need so if it's truly cold out (below -20celcius for these purposes) I can put those big thick fuzzy wool socks on and they're not at all tight. Especially Tight fitting footwear is a nightmare if it's cold out.
These cheaper boots are perfectly adequate for warm hunting in Saskatchewan winter conditions, but they're not so comfortable to walk in all day, and they're big and bulky and quite heavy. I don't mind the exercise haha but once you're dragging an buck out in deep snow by yourself and your feet are extra heavy and more importantly having to move through much more snow with each step than something more compact, it gets to be a bit of a chore by the end. All part of the experience but I'm certainly going to read through this whole thread.