Tether Tools is having a Black Friday sale. Of interest to me is the Onsite Relay camera power system (AC and USB A or C) that's a whopping 58% off. Put the power bank in a weatherproof cover and Bob's your uncle. Unfortunately, the LP-E6P dummy battery coupler for the R52 is not in stock, and I can't find one at TT, B&H, Adorama, or Amazon (but Adorama has the LP-E6 coupler for $35).
Also, the TT website has the couplers on a 50% clearance sale. Why would that be? New models coming out...