Welcome D/M/D! Great to have you onboard LCT and welcome to MUSH as well!
The biggest problem I see with the tour that you mention is that we'd still need to figure out how to get from Whittier to Anchorage on our own. Also, I'm a little worried about the way that they don't mention anything about which hotels that they use. Also, the tour in Denali sounds like the Natural History tour instead of the Tundra Wilderness tour ... which is highly discouraged on the CC Alaska board.
Kathy - 4 nights sound good to me as well. Does that include the night in Anchorage?
Lee - as others have mentioned, you can always do a longer precruise. Vancouver as you know is a fascinating city with Victoria near by. Or you could travel north to Whistler and check out where the Winter Olympics will be in a few years. Or you could even start more south in Seattle and explore the state of Washington as well.
Masaki