I was in Northern Central SD in Mid-December and hunted in 50mph winds with negative 20 wind chills. I was concerned about the same things. Given I only had 3 days to hunt, it wasn't really an option to stay inside. The hardest part was keeping my hands warm. It wasn't terrible, though, as I would just rotate keeping my hands in my jacket pockets with hand warmers. The rest of my body was okay with the gear I had (head to toe in Merino Wool, down jacket, outer shells).
My dog seemed fine as far as being warm. She's a Springer and has a little bit of a winter coat on her. The biggest pain was the ice that accumulated on her paws. I used a whole can of Musher's Secret but it just kept piling up, sometimes making her paws bleed. If I had to do it again, I'd try boots on her.