Travel to Alaska has had a lot of discussion on the Canada/Alaska board. Due to pandemic boarder restrictions there has been much of in the recent years, but older threads should mostly be applicable.
I just a video about by a Youtuber who drove to Tofino to pickup a campertop last summer. She had quite a time getting timely negative covid tests. Other than that her travels sound like ones I've done in the past decade.
SW BC had major highway damages in Nov/Dec, so you should check highway conditions (DriveBC). The freeway from Vancouver north (hwy 5) may still have restrictions this spring. And Hwy may also have slow spots.
While I've seen season highway closures on Google Maps, I don't think they adjust travel times for winder conditions. In urban areas and well traveled routes current time estimates take realtime traffic into account, but they don't try to project those times into the future.
In the past the Mileposts book has been the go-to guide book for driving to Alaska. It was up dated yearly, though mainly that affected the ads for tourist attractions and some services. Open fuel stops vary with the year and season.
Looking at Google Maps, it offers 2 alternatives with about the same time and distance. Average speed is 53 mph.
The westerly one, through Seattle takes Hwy 99 north from Vancouver. This is a mountainous route with 14% grades, but currently it is the only way north that is open to all traffic. And right now it will be quite snowy.
For a fast freeway segment look at Sacramento to Olympyia, average speed about 63 mph. On the other hand, Hwy 99, Vancouver to Cache Creek has a 43 mph estimated speed.
The core of the Alaska Hwy, Dawson Creek to Whitehorse is estimated at 54 mph. Whitehorse to Tok is rated at that, but that stretch is notorious for its frost heaves, which in May could be extra bad, and slow you down to 40 (esp. with a trailer).
An alternate route that Google doesn't show, is somewhat longer, but I suspect overall easier goes further east.
I5 north to Shasta, then US97 through Oregon and WA. It becomes BC97. Stay on that through Kelowna and Kamloops. This bypasses the damaged BC highways, and the big cities.
Then Hwy 5 to 16, and job east through Jasper. Catch the Alaska Hwy at Dawson Creek.
The main alternative to the Alaska Hwy is the Cassiar, BC37. That's somewhat newer (as a fully paved route), and more remote wilderness.
While distances are pretty accurate, travel times are estimates, highly dependent on what speeds are assigned to particular stretches. Some travel apps let you specify speeds, others you just have to work with what they choose. My impression is that GM takes road type (freeway, hwy, street etc) into account, as well as a terrain (grades, curves). But I take such estimates with caution.
