RE: Solution? High powered neodymium magnets. Cut the insulation into 3
panels, one for each side of the tent. Sew or glue one set of magnets
onto the corners of the insulation pieces.

BTDT  and the problem you may encounter is whatever you use to attach the
magnets to the insulation material has to be able to withstand the heat in
direct sunlight.  I can tell you that Duct Tape won't do it.