I wouldn't go on any long trips and board my dogs unless it was a matter of life or death! My dogs are a part of my family and I would no more leave them alone in the house or in boarding kennels than I would abandon my kids! Luckily I have a family member who would willingly move into our house to take care of them if there was some kind of emergency but I would still worry.
Both my dogs were rescue dogs and I can clearly remember how upset and stressed they were when I first saw them in kennels. It took a long time to gain their trust and the youngest one still suffers from separation anxiety. If I were to board them they would honestly think that I had abandoned them and in their minds it would be the worst thing that could ever happen to them. I love my dogs far too much to put them through that and I honestly can't see my youngest dog surviving as he simply wouldn't eat!
I cannot understand anyone who can go away on holiday and have a nice time when they know their dogs are in kennels. We have always taken our dogs with us and even though it means we can't go abroad and have to make do with a caravan holiday at least the family is altogether.