We stayed in the Marriott before our August 2001 Mariner cruise from Alaska to Vancouver as part of Radisson's pre-cruise Denali tour package, and found it to be very good to excellent. Try and get a rate with breakfast included, or get your breakfast out of the hotel; al a carte is a big ripoff as in many hotels, but I recall it was particularly egregious here.
One side of this hotel faces north and on the rare (?) good visibility days, Mt. McGregor is visible from the upper stories, so try and get a room on that side.
I have no idea if they offer day rooms, Mark. Can't hurt to call the hotel (not Marriott's 800 #) and ask.