We now don't do holidays without the dog. Silly I know, but the only person that ever looks after her is my son (and his wife) and we have their dog if they go on holiday. We have now given up holidays overseas so only go on holidays to places where dogs are accepted. For weekends away and appointments, etc where we can't take her, my son has her. Fortunately, he often works from home.
We have kenneled dogs in the past, but I would rather do what you do and leave them with someone they love in a home setting. Our dog and three cats rule our lives, I suppose, but they enhance our lives.