Thanks very much for the info everyone & thanks Richard for the offer of a temp address.
I like the idea of registering with Manx plates, I've been wanting Manx plates for over a year now!
A little bit more info about the situation. The car is 3 years old on 11 June, a return flight on the 10th or 11th June would cost £264 + travel/parking at the airport, but really 11 June is 1 day late. A flight on 8th June would be £316 + travel/parking etc - it may be a bit busy. A set of 4 tyres is £600 (Mich Pilot Sports). In a visit to the tyre place last week, I was told that there's around 5mm tread all round, apart from the front edges (I have a Powerstation alignment).
I've always in the past bought a new set of tyres, what's the situation with tread difference between axles? I remember something about that it should be too much or the diff gets messed up. If I bought 2 tyres, should they go on the front or back?