DRL

All I can tell you is that the 2002 Prius (the only one with available DRL in the USA) does not shut off when the car is parked but the ready light is on ("still running"). Also there is no way of turning them off, when for example, driving through a Christmas Lights display. Hopefully someone from Canada can give you information on newer models with DRL.

Regarding the Classic Prius' DRLs: For the holiday lights example (I've also heard of an astronomy gathering), the simplest method is to set your parking/emergency brake to the lightest setting prior to turning your car on. When you turn your car on, because the emergency brake is set, the DRLs will not come on. If you are just doing a short distance/slow speed drive around the neighborhood looking at holiday lights, this short distance with the parking brake barely depressed (first click) shouldn't be too bad.

I know that I've seen a DRL-disable mod somewhere online for the Classic...

this person did post a PDF somewhere, but I cannot find it at themoment... perhaps because I'm not currently logged into priusonline Ido not see the document. 15)

2002-2003 US Prius did have DRLs as an option. 2004-current US Prius do not have DRLs even as an option. Since DRLs are required in Canada, there is the occasional discussion as to how to add DRLs to a Prius imported into Canada from the US... So, I'd suggest that the OP ask on the Canadian list: