Some of the gravel roads north can be trecherous, especially at speed or when wet. TKC's are popular for the big bikes, as are Heideneaus and Fullbore USA's. Everything is fine till you get to the shoulder or get run off the road.
There are adventure bikes for every budget. For lesser money the older GS's are great, even a V-Strom. For new, there's also the S10, Guzzi Stelvio, and the Triumphs - 800 and 1200. The triumphs are nothing like days of old. They are really fine machines now, some are saying the best. If you're not going to ride dirt, or only smooth dirt, a good road bike is also enjoyable. The new honda 700 is getting a lot of praise. You really don't need a liter-plus bike to tour.
Definitely take an advanced riding course. That's one thing BMW is really good about, getting new riders or old riders going again. Rawhyde is good for learning to ride a GS competently.
I've ridden pretty much all of them, owned a 'strom 1000 when they were first out, and have now landed on the Tiger 800XC. For me it checked all the right boxes. A trip north is coming up one of these summers if ol' lady ever gets back to work again.
I have one for primarily road and primarily dirt.
My tiger in touring form:
And my dualsport that sees tougher dirt routes. I'd probly take it to BC to ride the mountains and trails up there. Will do gravel roads at 70 all day, and tougher two-track jeep trails.