Big Bay 20° Mummy Sleeping Bag

I got a modular sleep system at the thrift store about $14 so I use that when it gets very cold if it's going to be 30 to 40° or more, I'll use my 20° Coleman bag just since it's lighter, but the sleep system is actually really quite nice, if very heavy. It's been nice for very cold weather. I'd love a quality, light, very cold rated quilt or bag but I can't afford it for a while unless something washes up at the thrift store again. In warm weather I use a hammock I also got there

A comforter from Walmart would not keep you warm in 20F. I would buy a 20F Coleman on Amazon. They're not as pricey or pretty but they're quality.

Mi first bag was Coleman mummy synthetic bag. 50$. Good till 32F, then you’re really cold. Second bag is Nemo disco 15F. ~300$ on sale. And I got Disco 30F for 200$. Coleman isnt compact but does the job. Nemo’s got some room at expense of worth but they’re compact AF

I’m a cold sleeper & bought a $40 Coleman mummy-style sleeping bag & it’s awesome! I think it’s rated for 40F but I haven’t used it at that temp.

You can get a foam pad for a little ground insulation and a warm Coleman mummy bag for cheap. With enough warm winter clothes, eg a polyester filled winter jacket from goodwill, bib overall ski pants, a wool hat and warm gloves you can probably be warm enough and use those clothes to get around outside if/when your condition improves. If it's really cold add a balaclava for your face.