I grew up in Sandpoint! It is a beautiful, beautiful place!
Bonners Ferry has the Kootenai River running through it. If you get a chance, about an hour away are the Kootenai River Falls...go see the swinging, walking bridge that crosses the river! It is near Libby, Montana. If you are curious...you can google it and it will come up. I walked across it last July...very cool to look down at the rushing river, worried one of the old, weather worn boards might break off!
Also, Bonners Ferry has a Pizza Factory! So, if you are missing the tri-community, go to Pizza Factory for dinner and you might feel a little better!
Good luck in your move. You will absolutely love the area! You are so close to Montana...you will love their rivers!!
Take a boat cruise at the city beach in Sandpoint. Not very expensive and you can take a dinner or a dessert cruise. It gives you a great time on the lake and takes you to see bald eagles and their nests.
There is a lot to do! If you love the outdoors, which it sounds like you do, you will never be bored!! Enjoy!!