Keeping a rabbit hutch warm

Here I've seen someone put bubble wrap over their doors of the hutch to keep heat in. Do you think it works?

You need to be really carful not to bubble wrap against the actual hutch as it'll cause it to sweat and then get damp from the inside. The best insulation would be something you could throw over the hutch during a cold night and take off again the next morning - such as an old rug or duvet covered with a tarpaulin. You ALWAYS need good air flow around the hutch as damp is worse for bunnies than a howling gale. It's best to leave at least one part of the hutch open to the elements ie. The wired door part but just make sure the bed end is snug and warm.