Hi Ladybird
No question is silly when it comes to MM and how you can assist your partner.
Not sure from you your post how long you are looking for to stay in Sutton. Do you drive, how far away are you from Sutton. I was curious about your dilemma and looking around Sutton not many dog friendly hotels, were you thinking of leaving it in the hotel which might limit your choice.
Are there no reasonable “doggy hotels” in your area. Are you or partner computer savvy to investigate options. There was a list of hotels on the Royal Marsden site but no dogs allowed. Some I found needs a bit of travelling hence do you drive.
Sorry I couldn’t bring better news but by now you may have resolved it. If yes why not put it onto your post to possibly help others.
Regards
Graeme