Please refer to the LOA posted in Pubs/Policies/LOA: Edmonton FIR - Winnipeg FIR

Edmonton (CZEG) FIR controls 1,400,000 square kilometres of high-level airspace inside the Winnipeg CZWG FIR controlling FL290 and above for the HUDSON, SEVERN and THOMPSON sectors. When Edmonton is offline this airspace is uncontrolled.

Why does this not show up on VATSPY/Vatsim-Radar?
The VATSPY/Vatsim-Radar repositories that hold this information have been updated to include this airspace, however they do not reflect on those utilities. Edmonton airspace is accuratly documented on the VATGlasses respository which will hopefully be made availible in Vatsim-Radar soon.