Sorry for late response.

If you wish to use a friends address as yours that is a private arrangement between the two of you and will cost you nothing. We have used our sons address for the last 13 years. Don’t call it PO Box or a Care Of address as many institutions won’t accept this.

You will need a UK address for you’d bank, credit card and driving licence and more importantly, a postcode, it being the first bit of information that many companies ask for.

In our own case, our son will just scan or photograph any documents he think are important and email them or, more likely now, use WhatsApp. If he has to send a physical copy then we use the Poste Restante service offered by the Post Office (but not all POs will accept it. You will have to ask)

If you intend to have a car whilst cruising then you will need to inform your insurers as to where the car will be kept overnight. There are a couple of Brokers who specialise in car insurance for CCers.