Lest you think folks are ignoring you
I'd make your way up the Rocky Mountain Front via US89 to St Mary if your rig can handle the hills. Much more scenic than the Interstate.
I would also recommend basing yourself in the St Mary area for the duration of your visit.
You can stay at the St Mary CG(see rules about generator use) The park has a LOT of rules imo... Not so many at the KOA and Johnsons.
There is a KOA at St Mary as well as Johnson's CG which cater to RV's like yours. Both take reservations and both have nice views from the big RV sites.
And I highly recommend making reservations....and early if you can.
St Mary is centrally located for the East side. Two Medicine and Many Glacier areas are less than an hour drive. Logan Pass less.
I say stay in one place and drive your truck wherever you want to go.
Drive less and hike more is my motto
Mid July is
usually very good for flowers
most years.
That said, it's always a crap shoot on when the peak time comes.
It's very weather related as you probably know living in Colorado. A big snow year may delay blooming.
Regarding the West side. You should go spend time on the West side and sight see.
The Alpine section of the Sun Road on the West side should not be missed.
Not that big a deal to drive from St Mary to Apgar.
You can't take your camper over the Sun Road. Way too long.
I nag folks to get on the road early. It's just dumb to spend your precious time driving around in the traffic in the later morning.
Early is better for seeing animals, the light is better for pictures, and FAR less hassles driving and parking.
And it WILL be busy in mid July.
I'm sure you'll get some other ideas from chatters with kids regarding hikes and other activity.
pete