I did the Anchorage to Vancouver in 2010. Hired a private van that accommodated 15 and shared with another family. The Ak Hwy 1 and 9 is a beautiful drive. I am taking my daughter's family in late May '24 and will be originating in Vancouver to Seward. I found one option from an individual who operates a transportation service to and from Seward/Anchorage. I have not reserved with this service but the contact I had was professional and should be good. Because it is an easy drive, I may rent a SUV or mini van to haul my crowd as my flight does not depart ANC until 9pm. Good luck in your search!
PJS Taxi & Tours Renee is your contact... https://www.pjstaxi.net/