I thank you for the question.
It's always possible, but it's difficult. It's still possible to do studies in French and it's still going to be done. It's a bit harder to publish, but the main thing to ask is what you're going to publish, why and for whom. If one wants to publish to win a Nobel Prize, it would probably have to be done in a language like English. If you want to publish to inform policy-makers of scientific results, you should do it in their language.
We all benefit from being multilingual. Our French language is essential and fundamental. We will continue to publish in French. Even if it is more difficult, it is possible. But we need help to do more research in French and to publish in French.
We also teach in French. We have institutions in Canada where they teach in both languages. Indeed, when I travel abroad and deal with the internationalization of higher education, people always talk to me about Canada as a country where you can work in several languages.