Leaving the family behind.. Ever done it?

So, some of you know how worried I was about leaving the "kids" for a week or so. Well, my Grandmother asked me to stay here and live with her for a couple months. So the dogs (along with all the other animals) will be cared for by my parents. I'm scared crapless!

I know their basic needs will be met (food, water, shelter) I'm just worried they won't get the physical and mental stimulation they need to thrive. Especially Sky! I've told my Flyball coach she's more than welcome to keep working with him, or just letting him run around with the other dogs but I don't think she'll have time with her 5 month old BC keeping her on her toes. My step-dad may take them for the occasional fair-weather walk, which Sam is content with but I need some ideas on easy ways to keep Sky busy and thinking during the day.

Gosh, I am totally in worried mom mode right now. But I know that people, especially family, have to take priority over dogs. But I feel guilty because these are animals that I have taken responability for, and I feel like I am abandoning them.