How cold is too cold for outdoor rabbits?

[Strix]

What do you do to keep your rabbits warm enough in outdoor hutch? And how cold when they need to actually come inside?

Ive never bought my rabbits in. They have an outdoor cage but are free in the gardens.
We've had them 4 years now.

We used to cover the front wire mess at night which seemed to work fine. Oh and give them lots of hay/straw.

My bun is outside all year round. Extra straw and hay in the winter, and tarpaulins to keep wind and snow out of the hutch.

Ok. We have a hutch cover, and put in a small cardboard box and filled with extra hay.

But there is only one rabbit at the moment. Sadly his sister /companion died last week. We are getting another inna few days. But I'm worried he has no one to cuddle up with in the cold.

Mine is a solo bun - she is a rescue and had been terrified by other animals, so the charity we got her from recommended she stay alone but with lots of human interaction. She seems happy enough and is very affectionate, snuggling into my hand and licking us like a puppy.

Thanks for your responses. Helped me sleep last night.

Straw is warmer than hay, put a cardboard box full of straw in the hutch and you could cover with a tarp if it's wet. Goes without saying you should have a run attached to the hutch too, shouldn't be locked in a hutch, so the tarp can cover the run too.

You can get snuggle safes to use if it gets cold i.e. Below zero. If the rabbits are otherwise fit and well they should be ok.

Apparently rabbits cope better with cold weather more than hot. I worry about mine still and have a hutch cover, blankets (suitable for rabbits), hot water bottle (for rabbits) plus plenty of straw and hay. They are only locked in their hutch at night but when we are home have free roam of our house and garden although they come in and out seem to prefer being outside.

Some purebred can't cope with the cold, but other than that they seem fine.

I remember watching one sitting in th garden attempting to find some grass under the snow. Snow was still falling, and would settle on his back. Every few minutes he'd give himself a wee shake, but he wasn't particularly bothered!