Obviously this isn’t going to be the case for every dealer as other will be more strict but when we ordered my mums car recently she had been to a dealer sat inside liked it but we were still looking, when it was time to order her chemo was too much and she couldn’t go to a dealer, I explained this to a dealer and we did a video call with mum, of course I’m sure this is all not part of motability rules but as you say the only other way is to become an appointee and that’s a headache. The dealer was super nice and my mum didn’t have to be there for the order or collection but please take this advice with a pinch of salt as like I said every dealer will be different. I’m only saying it as it seems like your wife health isn’t the best and I know it can be difficult