If memory serves me correctly (and there's a good chance that it doesn't :lol
you're supposed to use a hutch snuggle underneath a hugger, not on its own, although you can use a hugger on its own. A snuggle is insulated so keeps the heat in the hutch a bit better; the hugger is waterproof and stops draughts and rain getting in the front, and also stops the snuggle from getting wet. Wet insulation will just draw the heat out even faster.
If it's one or the other I'd get the hugger and go get some of the shiny silver type home insulation from B&Q or somewhere to put under it