Then I opened my electrical panel and found this:

The main service conductors come into the panel from the top left, just below the yellow sticker. These bad boys are thick and sturdy, and placed far too close together for me to get the CTs clamped on. Better yet, I can't de-energize these cables in order to feed them through the CTs - that would have to be done on the BC Hydro side of the circuit.
So that's it - the monitoring experiment case is closed. BC Hydro does offer reasonable historical billing data, however, so I may still grab coincident weather data and run a quick model to check the efficiency of my home. The TED will be passed on to some lucky colleague at work to play with - I hope their electrical panel is easier to work with than mine!