I've just returned from walking Le Puy to Cahors. I don't speak French, but I am competant in German at the phrasebook level. During the first week, there were two fluent Francophones in our group of five, so they handled all the necessary and casual interaction in French. After that I was on my own. By this point, I had lodging reservations set up about four days in advance (imposing on French speakers at my lodgings to assist), and I was able to manage basic restaurant instructions, which was enough. I still cannot handle directions in French (guess that's what I'll work on before next year's trip).
I encountered very many Canadians on my walk (there can't be anyone left in Quebec, it seems); almost all were bilingual to some extent and so made for very sociable walking companions. Pilgrims from the German-speaking lands (Germany, Austria, Switzerland) were quite ready to converse in good English. The Dutch and Belgians were also very comfortable in English. However, I would say at least three-quarters of the walkers were French.
Not speaking French, I was able to manage the essential activities of travelling, but missed out on the dinner table conversation and other interactions unless I lucked out with English-speakers.