Does compressing sleeping bags so much affect their ability to retain heat? Bags naturally lose loft, will tight storage damage them? Most manufacturers advise loose storage for that reason.
I almost forgot, there is a remedy to crushed holofil.
I had a pillow years ago and on the tag it said to make the pillow like new and make it fluffy again, throw it in the dryer on high.
Well it worked perfectly and the pillow returned to it's original condition.
I thought if it worked on pillows, it should work on my mummy bag as well, and it did the first couple of times.
BUT.... I went to another laundromat and did it again, but this time the dryer was apparently a Hell of a lot hotter, it ruined the nylon shell, melted the foot to the center, had to throw it away.
But if you have a bag with a good shell, should work well.