My favorite, MukLuks. I have Camuks and the Quetico tall, which is all moose hide; the latter I only use in the snow. They’re extremely lightweight, cozy warm, and great for not tracking snow into my IC. They’re like insulated slippers and I even leave them on when I sleep in the shack. They pretty much utilize an insulated liner and an insole. For those that want to increase warmth, you simply add another insole, but you need to order two sizes larger than your shoe size. Mine are one size larger to accommodate thick socks and I’ve never needed more than one insole.
Back when I had an office to go to, I’d even wear them to work on those snow days and keep them on when I got to work.