how soon can a bonded pair be housed together at night?

Once a pair of rabbits have started grooming each other and lying next to each other how soon can they be left alone together at night? I don't want them to bond then to have to separate them at night, but I also don't want to think they are okay and open the hutch to find one badly injured or worse. I have a new hutch for them both so the bedding place will be neutral territory too.

Thanks

I'm very much of the 'bung them together and let them sort it out' philosophy, but the buns I have bonded have been very easy,and have got along straight away.
I would say if they have spent a whole day in their new hutch and there have been no huge fisticuffs, they should be fine overnight.
I know some people spend the night in the same room as their buns for the first night so they are on hand if there are any problems.

Thanks, they are in the kitchen at the moment (neutral territory) and are mainly ignoring each other and eating but every so often they will have a fight and lots of fur goes flying. I try and stop these asap but so far I think they are scuffles rather than proper fights. At least my male has stopped trying to mount. No sign of love between them yet but I'm hoping it will come eventually.