If you have the money (and time) for it, you could cruise on one of several lines from ANC to YVR (7-11 days), then take Disney on a (5-6 day) cruise from YVR to LAX. I'm sure the kids would love that part of it. The only hard part of the journey would be the ~10 hr drive to TUS.

Since your father is a private pilot, perhaps he might be able to fly you on the last leg rather than driving. LAX to TUS is about 500 miles, well within range of most private aircraft that can seat 4, and less than 5 hours flight time on even a slow single engine craft. (And no TSA.)

As of late May, 2011, the cruise port at YVR only had WTMD, and I believe that to be the case at the cruise ports in ANC and LAX.

The only problem with doing the cruise thing is that you would need a passport for YVR. I'm not sure if the children would need passports. The last I heard, minors under 16 could enter Canada and return to the United States by land or sea by presenting a birth certificate and photo ID. I'm not sure if that is still the case.