kennatt said..Interesting but Would think about impossible ,for instance how would you make progress along any stretch where the wind was head on. A short tack on even a very wide highway,dodging truck, would take all day to gain any headway. If set up with ballast on one side,what happens when the wind changes direction and is now from the other side .The wind would need to be at right angle to the road. Then of course you would soon attract the attention of the local Mounties. But interesting idea
I'll stick to my local beaches,its hard enough to dodge dogs,,,horses, walkers, pot holes and wayward seagullsl

If only we had your beaches. I saw that there's a tiny Blokart group in Ottawa, and they get their thrills on the Canadian Tire Centre parking lot. Not quite the same.

(Though they probably have a seagull or two flying around the parking lot garbage bins, lol.)
More research and thoughts on the idea:
Wind: I pulled down 20 years of hourly weather data for stations along the route and analyzed it, and it looks like once or twice a summer a system moves through that gives good wind along the whole route. Apparently a counter-clockwise low pressure system moving west to east with its centre a couple of hundred miles north of the Trans-Canada Highway is a classic pattern. (It happens more often in winter, but there ain't no way I'm heading out on a windy day in Alberta in winter. Let's see... looks like the record windchill for Lethbridge is -51 Celsius, lol.) So the wind is theoretically possible, but you'd have to pick your time and day like ocean racers do.
Police: The Alberta traffic act actually mentions wind power alongside muscle power when it defines what's not an off-highway vehicle! I wonder what wind-power enthusiast got that one slipped in. No such luck in Saskatchewan or Manitoba, though, so, yeah, probably lots of stops by Mounties along the way.
Trucks: A trip from Medicine Hat, AB to Winnipeg, MB would give you a divided highway with a decent shoulder the whole way, so that would eliminate trucks coming from the other direction. It's regularly traveled by cross-Canada cyclists. There'd still be transport trucks passing you in the same direction, though, so you'd probably want a support van behind you with big flashing lights advertising that you're a (comparatively) slow-moving vehicle.
This is sounding less like an adventure and more like a logistics operation.