Pretty sure that was the same Terra Nova hill we rode in a winter adventure race years ago - except we went downhill. We pedalled up the hill too, but on a different road farther east. It’s a crazy hill!
Wow! Good for you! Three years ago when my Mom and I did some Bruce Trail exploring in the Dufferin section, we stayed at her elementary school teacher's place, very close to Avening. Mrs C (of staunch farming stock) took us on a crop tour (in my car) that probably included that hill....she was eager to see Paul and I come back for a visit and ride our bikes up it. After your glowing report, I suspect I would be walking it, like I did some of the hills in the Eager Beaver a couple years ago (gravel race out of Duntroon). The downfalls of living down here in the flatlands........