Looking for advice, sub zero camping

Go with the -20F bag. Sleeping bag is not where you want to be cutting weight in the winter. 1lb is hardly noticeable and certainly not worth sacrificing ones sleep. Suffering sucks. Take the bag and have a good time.

Plus one to what Garrett said. Taking just the bag will be so much less of a hassle than dealing with a two part fiddly system not meant to mate with each other.

I think the xtherm plus zlite is a fine pad system for those temps.

Thanks guys! Do I have to factor windchill temps when I’m in a tent? I’m using an Xmid 1. Probably leaving the inner at home.

I was out last week with the temp dropping to -2 (snotel site nearby) w/ a 20 degree down bag and a 50 degree Apex quilt.  I was fine, but it got a wee bit uncomfortable by morning.  I was anticipating temps around 10-15, which I would have been down right cozy.

If they are calling for -5 temps, it could easily turn into -10 (or more)- I would go the safe route and take the -20 bag :)

Do I have to factor windchill temps when I’m in a tent?

Depends, can you pitch the fly to the ground? Silnylon is waterproof/wind proof, so as long as you don’t have drafts coming in through the bottom you should be fine.

Whut Garrett sed. Take the bag. Winter nights are not only cold they are L – O – N – G …

I have a nice -20 F. down bag and warm (5.3 R) insulated air mattress that makes my winter nights cozy – inside my TT Moment DW tent, that is.

Yes, I can pitch right to the ground other than needing some air movement to reduce condensation

In a stiff wind, you’ll get enough circulation of air through the tent even if you pitch it tight to the ground.

Wind chill describes the effect on bare skin. The more wind-proof your clothing, tent, or sleeping bag, the less effect it has.  Your exposed face would be effected and a loose sleeping bag hood would have more air exchange in the wind. Bring a buff or some covering for your face and a warm hat or hood for your head.

And, yeah, the -20F bag. That’s a no-brainer.