10 days of parking at MSP would be a killer. A limo is an option, but still probably pretty pricey round trip + tip.
If you are flying out of MSP before noon, you might want to consider a park & fly hotel stay at one of the hotels near the airport. We do this routinely, and find it is a nice way to start our vacation early, and to not stress about getting to the airport. This morning I booked a park & fly at the Grand Lodge, which is connected to the Waterpark of America, for our Jan. WDW trip. I got a King room, with bunk beds and a sleeper sofa, for $169/night. Your kids would probably like the limo ride, but would think you were a rock star if they got to play at the Waterpark before their trip (I have a 13 yo, believe me, I know these things and I polled him...he said a waterpark over a limo ride any day).They have free shuttles to the Mall of America and free 24 hr shuttle service to both terminals. They have heated parking and there is no max. on the number of nights you can leave your car there. We did not get waterpark passes included, but there are options for that. We'll probably hang out at the Mall and have a nice dinner before our trip this time, instead of doing the waterpark thing.
Both Marriotts near the Mall/Airport are good park & fly options too.
