I have a 20° Phoenix and 20° Burrow on order figuring I can use them from 20° up to about 60°. These will be my first quilts. Living in the South, for warmer temperatures, I'll use my 45° sleeping bag as a quilt with the 20° Phoenix or if temperatures are going to be warmer at night, I will try my SeaToSummit Reactor Thermolite® Liner as a TQ with the 20° Phoenix and see how that plays. I have a funny feeling that I will eventually wind up with a 40° TQ as my 45° sleeping bag ways a projected (as I don't have my TQ or UQ yet) 16 ounces more than the combined weight of the 20° Phoenix and 20° Burrow