I live in the wilderness of Denbigh (K0H 1L0), about 1.5hrs from Ottawa - 17 to Renfrew, 132 to Dacre, 41 to Denbigh, or 17 to Arnprior, white Lake rd. to white Lake, Burnstown, Calabogie, Matawatchan, Vennachar, Denbigh (or loop it). Lots of back roads, dirt roads and ATV trails that I think are what you are looking for.
a list of just a few of the 4x4 caches in the area:
GC50FD, GCP173, GC1328G, GC1P818, GC1QAKC, GC1PXPZ, GCW13W, GC1EXB2, GC1H428, GCW14Y