I think less said to insurance co, the better, so my priority would be:
1. Make sure they are all in places where they won't get stolen.
2. Move house
3. Tell insurance your new address
4. Move bikes to new address.
If bikes are at different places, and one got stolen, it could always be that you were storing it there after visiting and falling ill, so got driven home in a car?
Or, if you have a smsll broker eg Peter Hames, you could ask in advance, saying "what if i were to do xyz?"
Realistically, if you dont have a bike worth £5K+, I'd just make sure they're very secure.