Looking for a -20 synthetic sleeping bag

I am doing some extreme cold weather camping in Jan. Weight isnt an issue. Will be pulling all my gear on sled. Night time temps will be around -5. Needs to be synthetic and a wide cut. I looked at the Alps Mountaineering Blaze -20 but its only 130 bucks. At that price I would be worried it would keep me warm

Sorry, not much help here. I played with synthetic bags over the last year (a Thermarest quilt, and a Thermarest 20 or 30 degree bag, I forget which.) I never got to push the limit on the bag, so I can’t really give you reliable information. However, the 40 degree nights I spent in it, it worked just fine, and the build quality was good.

Having said that, I think it’s also relevant that after my little experiment, I went back to my Thermarest down quilt and bag. I do have experience with both of them. For some reason, I’m not sure they list the actual EN ratings anymore, but they did when I bought them, and the 30-degree Comfort rating was dead on. Very nice build quality - 650-fill down, so they didn’t break the bank, either. (Found both on sale.)

Pay attention to the EN ratings; they appear to allow accurate comparisons. As far as brands, what about Kelty, Big Agnes, or Sierra Designs?

I have a 0 degree Hammock gear Burrow Quilt and an EE Rev 0. I could combine them but at -5 I think i might need a full bag. I will be in a Snowtrekker Hot tent with a wood burning stove but when the fire goes out in the middle of the night its going to get cold

Whatever bag or quilt you choose, it will need to have at least four inches of loft above you, that is, a mummy bag will have 8 inches of total loft. Most manufacturers don't tell you how much loft their bags have, but if you're buying in person you can see for yourself. Their temperature ratings are deceptive, as they sometimes only list the "survival" rating, which is much lower than the "comfort" rating.

I have only limited winter experience, but I have slept on the snow at zero degrees in a Trailwise Slimline bag with 7" of overall loft, 60 percent of which is on top, so about 4". Wearing long underwear, wool pants and sweater, down booties and stocking cap, I was warm enough, or would have been if I'd had an adequate pad (I had only a 3/8" three-quarter length pad.) I'd suggest taking a self-inflater AND a closed-cell pad.

Down is the obvious choice for low temperatures, as there's not much liquid water around, but it's expensive.

Yeh, Im taking REI camp bed. It has an r value of 6. I think I should be ok it. PLus I will have 50 pound dog in my bag too