Cross country 3300miles with 1000lbs of junk in the bed and boat in 3.5 days. Sienna may give you trouble with front wheel drive on a ramp . . . Otherwise with with a tow package installed you should be "ok".
Honestly . . . I just picked up a 2002 Yukon 5.3 with tow package for next to nothing . I wish I had done it a long time ago. It's a tow, dump and wet dog mobile.