I think having your father in law come is the best alternative. I have certainly boarded Lilly and Honey in the past, when I didn't have a petsitter and the kennels were large enough for them to stay together in an indoor/outdoor run. But kennels, no matter how nice, are noisy and stressful, I think, especially when dogs are used to being confined. My girls always did fine, but were also always pooped when they came home.

The best of all worlds was when I found my petsitter through www.petsit.com and now no one ever has to leave anymore. They get to stay home and she comes two-three times/day and plays and loves on each of them (including the cats and birds). It is not cheap to have a petsitter, but I definitely recommend it over boarding, anytime. I should say that my dogs are not in crates, and Honey, Lilly and Zipper stay outside during the day when we are away. Murphy stays indoors. But if your father in law will come several times a day, for that long of a period, they should be fine!

Good luck, and try not to stress too much!