If you do venture on the Dempster Highway well past Eagle Plains enroute to Inuvik, I would recommend carrying more than one spare tire due to the sharp shale rock sections that will work their way thru tire tread and inner belts that are famous for causing multi flats, even with quality tires.
Some get lucky and never gotten a flat tire on the Dempster, others get one flat, and others can get two and way more flats on a single trip as one canadian trucker that drives that route a lot explained to me - some days it doesn't matter upon quality tires and driving habits that you can control, but it does help if the conditions are right not to potentially get a flat.
When I ventured on the Dalton and Dempster Highways, those were the only times I ever prepared to carry two spare tires for two reasons, along with a plug kit and an air compressor that I always have onhand anyway.
1 - The severe remoteness of regional area where services are real limited and the potential delays of tire repair in those parts if situations arise which could happen that the tire mount machine is broken or the mechanic is not on duty, etc...
2 - The intermittent sections of shale rock on the Dempster and intermittent sections of hard volcanic rock on the Dalton.
With those two potential reasons alone, in my opinion one would be a fool not to carry at least two spare tires with a non commercial rig if venturing along these two routes - unless you happen to be some royal sheik or one with influential clout that can make things happen with a snap of the fingers no matter the situation.
A friend of mine from southern Alberta ventured on the notorious remote North Canol Road in the Yukon and made it to the NWT border in his 1944 Willys Jeep, he carried two spares and ended up having five flats in which the plug kit and compressor is what really saved him to get back to his camper and trailer based on the east Campbell Highway.....He was down to one remaining plug after that adventure and was so happy to see a garage open on a Saturday morning when he arrived at Watson Lake to have extensive repairs done on the two flat spares.
Although I never quite made it to the shale rock area of the Dempster highway past the low 200km mark - since 1985 going on 33 years of travel here in an RV or passenger rig, on most every main road and a handful of remote side routes in the far north of Alaska and western Canada upon a full day or full month distant road trip.... I have yet to ever have a flat tire incident happen to me - with the one exception in Washington State outside of Chehalis driving thru a vacant lot with broken glass and developed a slow leak in 1990.
Other than that, I normally carry only one spare tire at all times.