For a camper van, I’d like to add temporary insulation in the winter to cover the windows and the metal walls.  Can anyone recommend a type of insulation that is:
– flexible (the surfaces are too curved & irregular to accommodate rigid panels)
– dust-free, since it will be exposed to the cabin, where I have to breathe it
– not too thick, since the cabin is already tiny?

Are my only options blankets or the hated foil-faced polyethylene?

Condensation is a big problem in such a small space.  Is closed-cell insulation better than permeable insulation, so moist air can’t get behind it to condense on the cold outer surface?  Would condensation be alleviated by putting insulation right up against the metal wall, or is it better to hang insulation as a type of curtain with a small air gap?  

Thanks in advance!