I've done the Canada/Alaska trip Arctic Circle trip on both a Moto and Last year in my 9mpg Tundra.
Seriously, fuel is really a non issue with a minimum of around a 200 mile range. The further north you get the more expensive it gets, but its still plentiful.
I saw folks with obscene amounts of fuel on their roofs and such on the trip, and although i get "being prepared" there is also being silly and dangerous.
Only fuel issue i came across (3x) was in the middle of the night. I do a lot of boring highway miles at night often.
Most of the fueling places up there arent 24 hours like most of us are used to. Most close between 9-10pm. I knew this and slept at 2 of them on my trip to wait for them to open, on purpose, good stopping points. They are used to it and allow it.
If you're like 99% of most travelers, and travel during normal daylight hours, with at least a 200 mile range, excessive fuel is just dead weight IMHO.
I carried one of these, and never needed for myself, but did use it to help 2 other travelers that were planning savy when it came to fuel, great product that works well:
https://www.gastapper.com/store/p1/Standard.html
Personally, id ditch those Jerry cans on the roof and use the space for something more useful.
My .02