Thankfully I can binge-watch movies on planes quite happily!

Thanks for the replies so far. I worked out 5 individual stops that came to about 250 dollars, a one way was 230 odd dollars so not worried about cost. I would just get a seat not a bed.
I've just heard about Sandpoint as I good stop.

So you have a ticket with 5 option stops or how does it work ? Either way in just about all of these places you stop you’ll need a car to see much.
Yes - it would be interesting to know whether it's a "five-stop ticket", or that you have just six individual sectors.
And what stops are they - if you wish to share?
Google Maps shows the AMTRAK Station in Sandpoint is right in town ... couldn't be better placed really.
We stayed at the La Quinta Motel there - perfectly okay, and had a nice pool area.

If no car looking at some of the stops I’d probabaly get off in Whitefish, Sandpoint, Leavenworth, West Glacier. Three nice little towns with lakeside or Mountain View’s. West glacier seems to me the closest stop to something interesting in the park. Looks like you can walk to the visitor center and even Lake McDonald from the Amtrak stop. I’m not sure the colombia gorge area without s car is worth getting out at so you can just enjoy the scenery. I wouldn’t stop anywhere in eastern Washington.
If you want to stretch your legs between Minnesota and glacier Montana I’d consider either Williston for the weird rough and tumble oil town vibe it has or The stop on the ft Peck Indian reservation if they are putting on anything cool while you are passing through. The grand forks stop seems weirdly to be way out of town.
Bearing in mind that wherever the OP gets off, they're there for a 24 hour minimum. I would probably include Spokane ... there are worse cities to wander around for a day.
The grand forks stop seems weirdly to be way out of town.
Back in the day when the railways were laid, I guess they made a punt about where a town would eventually be ... maybe they sometimes got it quite wrong.
We have more than a few suburban railway stations here in Melbourne that are a long way from where the shopping centres have developed - to the detriment of both.

OP--this is usually how train threads go, unless you're talking about the DC-NY corridor which people know well, which is to say people complain a lot about the train but lack experience. I have not done this routing, although I've done long distance trains in the US including the old northern route. I think you may do better (1) consulting the glacier national park website which has concrete info regarding train access (it looks simple) https://www.nps.gov/glac/planyourvisit/directions.htm and (2) looking at Tripadvisor which has a broad range of reviews--some whiny, some informative, for this route: https://www.tripadvisor.com/ShowUserReviews-g35805-d4713943-r562050038-Empire_Builder-Chicago_Illinois.html
OP--this is usually how train threads go, unless you're talking about the DC-NY corridor which people know well, which is to say people complain a lot about the train but lack experience.
What are you implying? We have been informed and informative ... I've visited nearly all the places the train travels to from East Glacier to Portland-Seattle, including Glacier NP and even little, peculiar, Essex, and have shared good advice with the OP.
Referring people to Trip Advisor is not only disloyal to the Thorntree, it is a horrible place over there.
From the NPS website:
Glacier National Park Lodges provides a shuttle (for a fee) that transports West Glacier Amtrak passengers between the train depot and Apgar and the Lake McDonald Lodge. Reservations are required.
Between that shuttle and the free each-way shuttle for the famous Going-to-the-Sun Road, I would have two nights at Apgar Lodge ... we stayed there one September and it was very pleasant, right on the creek and lake.