OK, I may not be that great on giving instructions, but I'll give it a try. lol Those doxie snuggle sacks that you can get? Here's how to make one.
The photo illustrates the concept.
Sew an extra long pillow case of your cosy fabric. The open end, pull it back to the end of the pillow. You can see where the doxie can go in. Secure the open end at the other end of the pillow if you like.
The other visual is rolling up a cuff on a long pair of pants, like up to your knee. lol You have a longish tube and double it up on itself.
Is that at all helpful?
Not only is winter coming, so is Christmas.