According to this map, the pre-unicity City of St. Boniface actually extended down pretty far to the southeast to what I presume must have been farmland back in the old days... looks to go at least as far as Windsor Park/Southdale, if not further.
Source: MHS
Huh. Ya learn something every day. Though I have to admit that I never would have thought anything southeast of Archibald and Fermor would have any claim to being part of St. Boniface.