Itinerate flights 150 miles from a miilitary airport will be under control of civilian ATC, not military, whether on an IFR or VFR flight plan. The terminal control zone around YTR or YTA is only about 10 miles. NAV Canada decommissioned virtually all UHF ATC frequencies a number of years ago with a couple of exceptions that you'll find in the database. The O/P was referring to the London area where there's no permanent military presence and no civilian ATC UHF coverage.