There are itinerant services provided in Thunder Bay, usually three or four times a year. "Local office" for most of NWO, last I knew, was still in Mississauga, albeit it appears that processing is grouped, meaning NWO applicants are processed as a group separate from other groups also processed in the Mississauga offices.
Fairly sure the Thunder Bay group for services includes areas as far west as Ignace. Not at all sure about Dryden.
If Dryden is not included with Thunder Bay area in the Mississauga office for processing, it will most likely be Winnipeg. Not sure where that office provides itinerant services.
Good news is that for routine applications for Thunder Bay they often schedule test and interview with oath to be taken within a day or three, or at least within a week. Bad news is if there is any reason to not proceed to the oath that quickly (basically while the team is in Thunder Bay for the batch being processed together) it will usually be at least three to five more months before they will back for another oath ceremony. Actual locations can vary around the city.