Bobstate, the ride is a treat, and if you suspect that you maybe ought to do it, then I think it works out that you MUST give it a shot.
I set out from Toronto a few days after turning 64, on a brand new Wee-Strom with a heap of satchels and suitcases, no top box and no saddlebags. I had no problems and considered the ride a total success.
I have ridden many thousands of miles in Ontario, and just as many in Florida since moving here in 1989. My longest one-day ride, before the YYZ-YVR-YYZ ride, was 444 miles, in 1965, from Nashville TN to central North Carolina.
I planned to take eight days for the ride westward, and I crossed Yonge Street at noon on a Sunday. I expected to reach Chicago by Tuesday and decide what to do next: roll the useless hunk of iron into Lake Michigan, rent a van and carry the bike west, park it there and go by bus, or simply keep riding.
I didn't reach Chicago by Tuesday. I didn't reach Chicago by Monday. I passed Chicago just before Monday began, in Central Daylight Saving Time.
I watched in awe as the mileage mounted, and reached 567 miles at a rest stop on Interstate Highway 80, about mid-way across Illinois.
I took six days for the ride, about half of the distance being on Interstate Highways, and half on secondary roads. I-80 is dull as dishwater in Iowa and Nebraska. I actually detoured to Denver and Golden Colorado to see some roundabouts, then I went north on CO-125 (wonderful ride) to regain I-80 in Wyoming, and saw terrific scenery in the western half of Wyoming. I wiggled my way to Arco Idaho, and greatly enjoyed US93 from there to Missoula Montana.
I visited the Grand Coulee Dam, then crossed back into Canada at Osoyoos, and went straight (well as straight as the road goes) to Vancouver. My daily mileage was 567 four times, and 495 twice. Six days, tenting four nights and staying in a motel once.
Coming back, I went through Whistler BC and up to 100 Mile House, then jogged back south, east, and north to pick up the Yellowhead Highway, which I took through Edmonton, Saskatoon, and some of Manitoba. I went south of Superior and followed US-2 to I-75, then south to near Flint and back through Sarnia, London, and Toronto. My return ride took five days, 454 miles the first day through BC's interior, then four days all over 600 miles.
I had generally good weather, from June 6 to June 23, 2006.
The same Wee-Strom has taken me to the other provinces and thirty-three states, and I rode it today in Sarasota Florida. It has covered 48600 miles, and has never given me the least bit of trouble.
I'm just an ordinary guy, with no particular training to enhance my stamina, and sure those long days were tiring, but I have had a few days over 700 mile, and one long haul from St. John NB to Toronto in one day, that is 878 miles. Lots of guys ride 1000 miles in a day, but I will never try that.
I hope you do the Vancouver ride. It will show you a country or perhaps two depending on your route, and if you go more slowly than I did it may show you some wonderful people. When you stop and meet them, they are pretty fine all the way out and back.
If scenery is your most important objective, consider BC, Yellowstone (I have never seen it), north of Superior (I saw that on another trip), and the Rocky Mountains (in both countries if you can manage it).
Then go again and have another look. That is what I plan to do in May 2010, on the same Wee-Strom, but this time from Florida.
Best of luck!