The (unavoidable) problem with visiting both Denali and Prince William Sound/Kenai Peninsula is that Anchorage is between them, with no reasonable way (in a short time) to bypass the city between the two areas.
I would actually reverse your order - Whittier/Seward first, Denali last - in order to give the weather and conditions in Denali as long as possible to move into "summer" status. While it might or might not make a difference next year, sometimes access inside the park in Denali can improve in that short a period of time, while it won't make much difference on glacier tours (Whittier) or Kenai Fjords tours (Seward.)
Here's how I'd time things in your case:
Sun 28-May - Arrive, overnight Girdwood (Alyeska hotel)
Mon 29-May - Glacier cruise from Whittier, overnight Seward (Memorial Day)
Tue 30-May - Kenai Fjords cruise from Seward, overnight Seward
Wed 31-May - Return to Anchorage, overnight Anchorage
Thu 1-Jun - Drive to Denali area, overnight Denali
Fri 2-Jun - Day in Denali - at least to Eielson visitor center, overnight Denali
Sat 3-Jun - Return to Anchorage, overnight
Sun 4-Jun - Depart
Girdwood is a terrific "first night" (it won't get dark) in Alaska - it's incredibly scenic and the drive there from ANC will knock your socks off. Splurge for dinner at the Seven Glaciers at the top of the Alyeska gondola.
Staying in Girdwood will make getting to Whittier very easy for a glacier cruise the next day. You access Whittier through a one-way tunnel from Portage Valley, which is just down the road from Girdwood. After the cruise, it's around 90 min. through more beautiful scenery to Seward.
Take as long a Kenai Fjords cruise as you can manage, but be mindful that some of this trip is on big water, so bring seasickness nostrums if needed. Spend that night in Seward too.
Visit Exit Glacier on your way back to Anchorage from Seward, and if you want a glimpse of an old mining community in a superb setting, take the Hope cut-off on the way back to town.
Take the bus as far as you can into Denali NP - Hopefully Eielson will be open (it's supposed to open by June 1, the day before).
Return to Anchorage for a last night before flying out.
Alyeska -
http://www.alyeskaresort.com/
Glacier tours -
https://www.phillipscruises.com/ or Major Marine (below)
Kenai Fjords -
https://majormarine.com/