TCF or TEF? Where do you sit it? How do you get a seat?

There is no general answer, because both conversion tables are set by IRCC and the same NCLC level counts identically either way. In practice the only difference worth weighing is format: the TCF's 3 writing and 3 speaking tasks are shorter and more fragmented, the TEF's 2 writing and 2 speaking tasks are longer. If long-form writing is a struggle, lean TCF; if you need time to develop an argument, lean TEF. What actually decides the result is your level and your practice volume, not the choice of paper.

No. The TCF and TEF centres on Ontario's official lists are concentrated in the Greater Toronto Area (Alliance Française Toronto's four sites: Spadina, North York, Mississauga and Oakville) and Ottawa (Alliance Française d'Ottawa, plus Algonquin College for the TEF and FrancoLangues for the TCF). Neither Thunder Bay nor Sudbury is on the list. A third-party exam-directory site has listed a Sudbury address; lakebbs could not verify it against any official list, so confirm with the centre directly rather than booking a flight on it.

Alliance Française Toronto's site states that the registration fee for both TCF Canada and TEF Canada is CAD 390. Cancellation or rescheduling has to be done 15 days before a computer-based test or 30 days before a paper one, and carries a non-refundable CAD 100 administrative fee. Add flights and a hotel from Thunder Bay and the true cost of one sitting is usually around a thousand dollars — which is exactly why it is worth getting speaking and writing to standard before you register, rather than sitting one "just to see".

IRCC requires language results to be under two years old when you submit your application (Alliance Française's TEF page likewise states results are valid for two years from issue). Treat those two years as a hard constraint when planning: credential assessment, employment records, entering the pool and waiting for a round all have to fit inside them, and an expired result means sitting the test again.

Supply is too concentrated. Essentially all of Ontario's seats sit at a handful of centres in Toronto and Ottawa, and everyone in the country who wants a French test is competing for the same releases. Alliance Française Toronto's site states that registration opens quarterly and is entirely online, that you may hold only one active registration at a time, that there must be at least 20 days between two sittings, and that full sessions have no waiting list — so missing a release means waiting for the next one. "Seats gone within hours of release" is what candidates widely report, but lakebbs could not verify that specific claim on the official site.