Thanks Bev, the problem with this is that neither of them will be owned by us. We will be renting during the winter and the summer and therefore these addresses are likely to change each time we move, since it's unlikely we'll get back into the same summer/winter rental each time. Does that make sense?
It's a tricky one and probably one that isn't easy to maintain, but we're hoping we'll be able to pull it off. Although like any country you need some form of fixed abode for paperwork and accounts, it's just working out the best solution for that.
Perhaps it's a case of paying a service to keep an address for us - normally used for businesses but I think i've seen some personal ones too - I think i obviously need to do more research!
Thanks again for all input.