I am sold on use of the cloak for limit objects. I allow the cloak to cover head but keep my mouth and noise exposed to air by careful adjustment of cloak all about the eye but allowing the mouth to be breathing if not to open air at least to an area of the cloak that is not going to leak much into the eyepiece area. Have to hold the cloak for this sort of approach. I think you could make some odd cyborg sort of full head hat that covers one eye like the borg in Star Trek but perhaps that is taking things a bit far ...
I also use a heated eyepiece in 'dew season' as I find just the heat off of the face/eye can fog an eyepiece when it's real cold.