To be frank, we stopped going away unless we could take her with us - e.g. to stay with friends. She was intensely attached to me, and although we’d often put her in kennels in previous years, once she was old with a few health problems, I couldn’t do that to her. Like you, we had nobody I’d have felt happy to leave her with.
Leaving her at home for half a day was fine, but no more. Very short walks ‘to do the needful’ were all she could manage.
She was half cocker spaniel - the owner of her mother never knew who her father was - she suspected some ruffian on a farm!
She was eventually PTS at 14 1/2, and TBH we should have done it a bit sooner.
We’ve never had another dog - I’d love one, but when you have nobody to leave them with - and kennels around here often need to booked well in advance, so no spur of the moment trips or whole days out - it’d be just too much of a tie.