Do you mean available for Montreal SP rates, or available altogether? Almost all pornstars do escorting on the side (although the number has dropped slightly due to OnlyFans and similar platforms), just be ready to pay hundreds if not thousands (even tens of thousands) of dollars to meet with them.
I used to travel to Europe, Dubai and the US in my previous job, and met several popular high-end pornstars who were advertising their services, either independently or through an agency (some also work under the radar) so it is possible…just need to know where to look…
I know from the ones you mentioned, Rebecca Linares used to work out of LA and Vegas. Not sure if that’s still the case…
There’s so many that I would still like to meet, but two that quickly come to mind are Jada Fire and Keisha Grey. Tried to meet with them individually but the schedules didn’t match, and i think they’re both retired from the escort scene…damn…