Advice for a part-time dog owner?

My parents both retired last year and decided to spend the winter away from the frozen land we call home. They went to stay with a friend who has her own animals so to make things a little easier my SO and I volunteered to take the dogs while they are gone. Both dogs are just over 10 years old and I have lived with them for several years until pretty recently so they're both familiar and comfortable with me and I know their routines and personalities so it was a pretty easy decision.

My parents will be coming home in a few days, however, it's likely they'll only be home for a couple weeks before leaving again for about 6 weeks.

My question is- do I take the dogs to see them while they're home before they leave again? I don't know how dogs react to that kind of thing. Would it be harder on them to see my parents and then be separated from them again? Do dogs hold on to that kind of thing? I know my parents would like to see them and I'm sure the dogs would be really happy as well but if it's going to make them depressed or anxious leaving them again so soon then I'll just wait until they're back for good (or at least for months instead of days!). Suggestions?