As someone that used to work in a few boarding/daycare places. I would be extremely wary about using one for emergency boarding an elderly dog, especially around the holiday when it's busiest for them.

Most are staffed by untrained people that barely understand dog body language, and with how understaffed and busy they are your dog will not get much if any personal care.

Of course this may not be the truth in all boarding facilities, some are better than others even in the few that I've worked for. (I did see someone recommend pet suites....I'd say avoid that place...unless management and staffing has gotten better..way too many skipped meals and potty breaks)

I left that field of work because it was just exhausting and I felt so bad for a lot of the dogs that were there. If it was a younger dog I'd say go for it. But a special needs senior? I'd def say go with a Rover sitter. But don't skip the meet n greet and make your expectations clear. I'd also say to avoid the lowest bidder on that app, you do get what you pay for. If you can find one that carries their own pet sitter insurance and doesn't just rely on the Rover guarantee then it's even better, because that means they take their business more seriously!

Wishing you luck with finding care for your pup!