Is there a reason you prefer the Fraser River route vs going up through Squamish and Whistler and Llilouet to Cache Creek? Just curious because I rode via Whistler in 2005.
I cannot comment on your ride from Vancouver to Cache Creek. After Cache Creek to Fairbanks, it is a nice ride and you should take these factors into consideration:
Leaving in Mid-May, you will encounter below overnight temps below freezing - especially as you get further north.
There are not a lot of huge climbs the entire way. However, the roads are rarely flat, so you are constantly going up and down short steep little "pain-in-the-butt" hills. It wears you out a lot.
The roads are mostly paved, but not smooth. Plan for your bike to roll 2-3 mph slower due to this.
When you get to the Cassiar, you might be hitting there when the bears are active and have not moved to higher elevations. And, there are no services for the first 100 miles of the Cassiar (when going north).
The bugs are terrible the entire way - drove us crazy.
As mentioned by others, there is not much in the way of bike shops after Smithers until you get past Watson Lake (north end of the Cassiar).
There is much more traffic northbound when you are going and the shoulders are not wide. On 97, there are a lot of "chip" trucks that don't move much. That all ends when you get to the Cassiar even though it is shorter than the Al-Can. Lots of RV going north at your time as well.
My ride is recorded on www.windrath.info
if you want to see our day-to-day stops and pictures.
It is a great ride with outstanding scenery.