I spent a week in Montreal in 1998, and due to my stupidity I have data.
I was there for a conference. I stayed at the (French speaking) UCaM. The important bits: it was three days before the Americans I knew arrived; and I didn’t know there was an English speaking and a French speaking bit of Montreal.
I’m Australian, and even though Australians hear the Pomgolian in my speech, others don’t. I have almost no French - I understand a little, but I can hardly talk at all. The first few days in Montreal, I opened conversations in shops the same way I have in Vietnam, India, Holland, France, Germany, Tonga, the Phillipines etc: in carefully pronounced, Australian-accented English, slightly apologetic I-only-really-speak-this-language-embarassing-but-there-you-go smile on face.
In Montreal, everyone was charming (except the beggars - well fed self-righteous beggars in a first world country get my goat). Even when I just wanted to watch the World Cup soccer in what turned out to be a gay bar. I had a great time. Nobody mentioned the language thing and nobody told me that there was an English-speaking part of town (where, as it turned out, the streets were clean and the food was shite).
Then everyone else I knew at the conference arrived, and I went around the traps with my mate from Detroit (and others). He speaks fairly good French (it’s his third-best language), but it’s with a US accent. We got sneered at. Daggers were looked on the street. We got told to fuck off by passers-by. I think we got spat at at the music festival. (I mean, holy fuck, I just wanted to see whether the Alan Parsons Project really still existed…) Totally different feeling. The first Montreal I liked. The second was rather ugly.
Really quite interesting.