Colin,
Have you spoken to a dealer, rather than motobility, if you know what you want, and the car is suitable for you, you used to be able to order over the phone, and sign documents digitally, (did it twice), although this may have changed. When I went through the ordering process this july, it was a lot of question and answers, yes and no, replies, on a screen to what is a live page to motobility, that could easliy be done over the phone. If you prepare digital copies of your driving license and award letter, sending them by email, and even pay a deposit. I don’t see a problem, you could even arrange a video call through facetime, or Google, to go through the order with the salesman. Speak to the dealer, see what he says, and how he could help. Where there’s a will there’s a way.