Long-term Bonded Pair Fighting

I have two bonded female rabbits, Daisy and Ivy. They are about 2.5 years old and have been together since they were a few weeks old, although they are not from the same litter. They have always lived together and, apart from a few scuffles before they were spayed, they have always been extremely close; grooming and cuddling for hours on end! Yesterday I heard some strange noises coming from them at night and when I asked my boyfriend to investigate, he found fur all over the place and they were tetchy and on edge - clear evidence of fighting. Today I set up the hallway for playtime/dinnertime as usual and they have not stopped going at each other. They have been nipping, circling and boxing; being very aggressive which is completely out of character. I suspect one of them is unwell but as it is Christmas eve tomorrow, the chances of getting a vet appointment in the next couple of days (at least one that doesn't break the bank!) are slim. What can I do to help them be as safe and stress-free as possible in the days until I can take them to a vet and find out what is going on? I worry that simply separating them completely would do long-term harm when it comes to re-bonding them.

I would suggest keep them close but separate. Its possible one is poorly or something. Get to the bottom of the problem then try and rebond. Good luck.xx