Vivian has recently built up the blankets in her window lounge box. Just a month ago, she had arranged her bed, but it wasn’t built up like this, and since things have gotten a bit more chilly, she has made changes that may keep her warm.. It’s quite messy, and there are hay pieces in there which she insists on adding and subtracting (normally by snacking on them –LOL, but she will also rearrange the bitty hay pieces too! ). And she then snuggles in a gets cozy.

So, unless your bunny actually likes to eat blankets (nibbling holes is normal), then you may just want to supply some snuggly warm blankets for her to use if she wants. I also recommend putting a blanket over the cage, or at least part of it if you think it’s getting too chilly.
It also depends on what a bunny is used to. I mean around here it can be nice and warm around 70 degrees (as it was just less than two weeks ago), and then wham, a 20 degrees difference. (lower), Not enough time for a bunny to molt in the fur they need, so depending on how fast there is a temperature difference, you may need to help keep things warm with blankets, etc until she gets used to it.