Best ways of keeping rabbit warm???

My rabbit is currently outdoors. I don't have a hutch cover but was wondering if it's okay to puta old duvet over the front of her cage until I move her into the shed for winter? I'm also hoping this stops her getting spooked and thumping at night if she can't see out as easily.
Any suggestions will be appreciated.
Thanks in advance

You could put an old duvet over as long as it is covered in something waterproof like tarpaulin. If the duvet got wet it would have the opposite effect and cool down the hutch instead of insulating it.

A lot of people here use duvets under hutch covers or tarpaulin and as long as it doesn't get wet it works very well.

I was given some good advice by a very good friend of mine who has a couple of guinea pigs. She has insulated their hutch using bubble wrap. I have now followed suit and having bought 50 metres of bubble wrap on ebay for £6, I have been able to fully insulate Muffy's hutch. All I did was use a staple gun to attach the bubble wrap to the outside of the hutch, and it can be easily removed in the Spring. I used two layers. Also, if it gets really cold this winter, I can add another layer. Cheap, cheerful and effective It keeps the hutch well insulated, dry, and Muffy can't get at it to chew

Milly x