Hi Donna, I lived in Fairbanks years ago and have returned three times as a tourist in recent years. We are going again next summer, to Denali in June for the wildflowers and midnight sun. And the mosquitoes!
We have not done a cruise but I know from reading the Alaska forum on TripAdvisor that the Vancouver to Seward one-way cruises are favored. If you have questions about which cruise line, you might ask there or on Cruise Critic, as different cruises have different port stops.
Adding time on land as independent travelers ( rather than a cruise tour) is the right idea. However, I wonder if you would consider renting a car rather than taking the train to Denali. Driving in Alaska is VERY easy as the roads are quite wide and well-maintained. And there are so few of them it is impossible to get lost. Taking the train up to Denali is quite expensive, and will leave you with very limited lodging and sightseeing options once you get there. I will post one notable exception to this opinion below.
Lodging at Denali comes in several types: 1. the fancy and expensive cruise ship hotels near the park entrance, in the area known as Glitter Gulch; 2. smaller and generally family-owned lodges and cabin resorts spread up and down the highway, mostly south of the park entrance; 3. an assortment of inns, B and B's, hostels, and lodges in the town of Healy, 10 miles north of the park entrance; and 4. wilderness lodges deep within the park, reached by their own private buses.
If you arrive by train you are pretty much stuck with options 1 and 4 because of transport issues. Unless you are able to book one of the few rental cars available from one of the lodges in Healy. But you would be using it only to get back and forth between your Healy lodging and the park entrance, and maybe to drive the first 15 miles into the park. Private vehicles are not allowed beyond that point; you must use the park shuttles for sightseeing and hiking within the park. Or book one of the wilderness lodges, which will transport you over the park road on their own bus.
And this is where my "notable exception" to my opinion on train versus car comes in. The wilderness lodges have schedules geared to train passengers. They pick up passengers arriving on the southbound train from Fairbanks around noon, and take them to the lodge in a 6-7 hour drive. Passengers arriving from Anchorage get in around 4 pm, too late for the lodge shuttles, so must spend a night near the park entrance before catching the lodge bus the following day.
There are four wilderness lodges out past Wonder Lake and they are all similarly priced ( I.e. Expensive). Two are such a standout in terms of quality, views, and programs offered that I will only stay at and recommend those. They are owned and operated by the same family and run the same programs and have similar menus ( with excellent food), but differ in the accommodations themselves, and the views.
Camp Denali ( where we stay) is a cluster of log cabins up on the hill with great views of Denali when the mountain is out. The cabins have a cold water tap but no bathroom, just a private and very clean outhouse for each one. There is a central bathhouse with flush toilets and nice clean showers. And a main lodge with dining room and fireplace, together with a smaller lodge that functions as library and meeting room.
North Face Lodge is at the bottom of the hill with limited views but the same great food and programs (guided hiking, etc.). It is closer to Wonder Lake if you want to borrow one of their canoes to paddle on the lake. It is a more standard lodge and the rooms have ensuite bathrooms, so more suitable for anyone who does not like the idea of an outhouse and central shared shower facility.
The other two lodges are Kantishna Roadhouse and Denali Backcountry Lodge. The four lodges all have various minimum stay requirements. i am out of space but can describe these later.