Some folks still think that the AlCan/Alaska Hwy is gravel and mud and that everybody drives like idiots. None of that is true. For us AK may have been an anomaly, while we have only been there three times, one driving all 12,000 miles, twice flying and renting an RV, we have been all over the state. Broken or chipped windshields are common but remember that those big rigs pay as much for a window as we do. Suppose they drive 20K to 50K miles every year, having to replace them every 60 days is expensive. When passing and oncoming semi, slow down, move to right and you just might be surprised to see the semi do the same.
Spare tires are not as important as good new or close to new tires, 6 years or older are not good for driving up and back. If you don't have a rim, don't buy one, carry an un-mounted spare.
I'd leave from Dawson Creek in May but I like snow and Ice. Best to check before you leave home on snow melt time and river breakups.
What we missed most in 2000 was having to come home. I can forget the phone now, but, I really like the internet. It's available most place now, but I think the DGD missed her phone.
So to enjoy more, drive slower, stop often, take pictures, keep a journal and don't hesitate to stop for something you MIGHT like to see. Take your power drill/drive and your sign for the sign forest. Plan on a few hours there. Just slow down and smell everything that you can.