What Activities In Glacier National Park?

Hi there

My family is going to be travelling through Glacier National Park from Seattle over to Minneapolis, and I wanted to find some activities to do on the way since we'll be stopping in Glacier. So far, I plan to stop in the Kalispell area overnight, and then head through all the attractions along the Going To The Sun road throughout the next day.

I need help deciding if I should stay an additional night to visit any other parts of the park, and where I should stay. I heard Many Glacier hotel was nice, however I don't know of many other activities that would appeal to my family. This is our first adventure type roadtrip, so we'd like to stick to the main attractions and nothing more than a moderate hike.

Note that this is part of a 3 week trip, and I'm already on the short end of time, so if there isn't anything that's a must see, I'd be best continuing on my way!

Anyway, after reaching the road end at St Mary, I would either stay in a hotel in order to do some other activities the next day, or I would drive down to Great Falls, MT and overnight there. Any advice would be appreciated! Thanks