If my Bayer wasn't stuff sacks & accessory cord now, that would be a good idea, even with a decent underquilt especially in the seriously cold weather some of us really like.

If it keeps the cold off of you, AND you can easily carry it, it is a good idea.

Just FYI, my hammock sock is similar material & added 10 degrees EASILY. Sadly, it no longer fits my Primary hammock, but that's ok, I can still use it around the house