OK I have bought at least a dozne different boots, and currently I still have an wear 3.
I have Danner prognhorns, not insulated that I wear all the time, for up land, and even fishing, and I love them. They were the last of the 3 boots that I bought, and had they been the first I would have simply bought 2 more pairs with different insulation values. And the ankle support is great, I hurt my ankle from a bike crash a while back, but these are good enough I can comfortably scramble up and down rocks all day in comfort.
The other boot I have is a discontinued browning. Sorry I can't rememeber the model, but they are 400grns of thinsulate. And the more important thing is, they are extra wide, though I have a normal sized foot. They sent me an extra wide by mistake, but after putting on thick sokcs they fit like a glove. Even with such little insulation, I'm still good to call in them down to about -25 C, with a good pair of socks. And even in dress socks, I still sit in a goose blind all day with these and have no problem.
The last pair I kept is, the Saskatchewan modle pac boots made my cabelas. Like all pac boots they are heavy, and hard to walk in. But OMG they are warm. At -40 they are still almost to warm. I always wear dress socks when I put these on, and when II say dress socks I mean the nylon thin ones at that. I am sure there has never ever been a day cold enough where I couldn't stay perfectly still all day with these on and get cold feet, they are simply that warm. I know I have spent the last few sentances saying how warm they are, but I really mean it, they are made for people calling in artic fox, and polar bears above the artic circle.
On and PS, driving a standerd import with the small little petels, with pac boats on, is a skill all buy its self, and should not be attempted for the first time on public roads.