Checking with Victoria BMW and the harness is no longer sold separate in Canada, it is only included with the BMW hitch.
Harness part number confirmed from Vic BMW: 71 60 2 156 526
VIC BMW Prices in CAD:
They quoted five hours total install at $120/hr
$870 for the complete hardware kit
$1680 total installed including tax
I ended up ordering the harness from ECS tuning (ES#:262790) for $210.29 USD
All in shipping, duty and tax will be around $305 CAD.
Link to part on ECS Tuning
Installation Instructions