hope he is better by then but if worst happens then rather than a wheelchair rental it might be worth a
scooter. I have done it both ways- but the holiday was so much better when I rented the scooter, and just used my chair for offsite shoping ect.
2 main reasons-
1- it is hard work for everyone to push the chair about all day (at least it is with me in it

)
2. In a chair you are sort of removed from any family conversations/fun etc.- I hate my chair for this main fact- so I try and use my sticks and push trolley until I am almost unable to move any further in order to join in with everyone more. You do not feel as removed in the scooter as you are higher up and not out in front of the others (wish I could stretch to one full time- but it would cost us our next holiday- so not going happen). Thus are less likely to stuggle through the pain to avoid the chair and end up ruining the day.
May be not everyone feels like this about their wheelcair but I would say no shout GET A SCOOTER. - they only cost about £100-£140/week. Not much to save a holiday