I haven’t been here lately so this might be late - I don’t do outcall in Montreal generally but there is a local board with lots of recommendations.
The board is merb.cc - but from my experience and from other feedback the best agencies are:
Euphoria (in/out):
https://www.euphoriagirls.com/Vogue (outcall):
http://vogmtl.com/Godiva (outcall):
http://godivaescorts.com/Escorts XO (in/out):
https://escortsxo.com/