Central South Manitoba (and maybe Winnipeg?)
This is a projection based on maps, databases, and some personal knowledge of the area's topography. Getting digital TV from the U.S. in this area is a real gamble for about a year. It SHOULD work for people in Central South Manitoba a bit north (as far as Winnipeg?) along that same belt, but all this certainly requires testing.
The target broadcasters are in Pembina and Grand Forks, North Dakota so obviously the closer you are to the U.S. border the greater your odds of getting them. Also, repeater stations dot the landscape all along the U.S. border so other reception opportunities need to be tested in your exact location.
Your gear would need to be a deep fringe setup such as a Channel Master 4228 bowtie reflector, or a very high gain yagi like a Winegard PR9032 or a CM 4248. Expert opinion is that the CM4228 performs best in fringe and deep fringe areas. No matter which antenna, you'll also need a CM7777 or Winegard AP8275 preamp.
If you are in a rural area and have an elevator, grain bin, or silo on your property you have a great antenna tower already in place by putting the mast way up there provided that the run of cable into the house is less than about 30 meters or you'll suffer line loss.
Your antenna should probably not be fixed into position at a specific azimuth unless Pembina is in a direct line with Grand Forks from where you are. For everyone else this is mandatory rotator country. Also, if and when Canadian stations go digital in the area, you'll be better off if you put your antenna on a rotator in the first place and had a CM4228.
Here are the digital stations from Pembina and Grand Forks, ND:
KNRR-DT 15.1 (FOX) Pembina
KGFE-DT 56 (PBS) Grand Forks
KCPM 27 (hasn't announced a DTV switchover from analog)
There will be plenty more analog stations available too, and the curfew for them from the FCC is for a 2006 switchover to digital.