Being at or north of the Arctic Circle on June 21 is an experience that'll stick in your brain. The sun stays above the horizon. At Inuvik, the sun is high in the sky all night. For folks not used to all night sunshine, it can be a bit disorienting. Hubby wanted to hit the road late in the evening because he was wide awake in the sun.
The drive north on the Dempster is interesting. Do check in at the Visitor Centre at Dawson City for the road conditions before heading up.
Tombstone Park is worth of a couple of nights stay and there's good hiking in that area.
Don't be in a rush - drive for the road conditions. Let the locals whip on by because they just need to make time and they know the road.
The
Yukon government's Dempster Highway Travelogue is a good resource.