Extra Tires to the Yukon?

In Nevada lots of people carry two spares, especially people that work on mines and chukar hunters. It is totally logical to carry two spares when the gas stations can be more than 100 miles apart. I have lost three tires in one day twice in my life. The last one was not that long ago.

We put 30,000 km on the truck to Alaska, Yukon, Northwest Territories in 2016. Only had the spare on the truck. Never needed the spare at all.
I helped an Austrian couple change a tire on their rental on the Dempster. They had it repaired at Eagle Plains.
The road is open all the way to Tuk now. Not sure what they are doing for camping up there though.
Enjoy the trip, it's worth the drive.

I carry an unmounted spare strapped up between the chassis rails plus the tools to change it if I'm desperate. Lots of tyre repair plugs too.
Plan B if necessary if a front tyre gets damaged is to take off one of the duallies for the front, pump the remaining tyre up to maximum sidewall pressure and drive slowly to the next town.

Heading up towards Tuk in a couple of months.

Did the Dempaster in 2015 ...crushed stone and mud road...some rough spots . Borrowed an extra spare for truck ,never needed but nice to have . Met a guy that had 2 flats in a 100 km streatch . Carry flat repair and insta flat can ....also I always have 2 spares for camper . Along the Dempster the first spot for a tire repair is Eagle Plains ,then ft Mc ferson ,then Inuvik.. The worst road I hit was Alaskan hwy from yukon / alska border to Destruction bay..

You will have some stretches of gravel due to construction. You'll receive mixed answers, I believe. We drove up on new tires to Alaska with no issues and many do, especially those with big motorhomes because they typically don't carry spares - tires are too heavy.

Then there are others that take two of everything... just in case. Do whatever feels comfortable for you. Very few people get flats on the trip and very few get broken windshields.

The best suggestion is to drive slow, especially through the gravel areas. This is one trip you can't rush. Have a good one!