Help with how to wire ditch lights to run off of car battery OR power station? Details in comments. : overlanding

I have been using my 2015 outback as a light overlander for a couple years now, and I was gifted an EcoFlow River Max power station. I want to run ditch lights on the OB for off-road driving, but also use them when setting up or tearing down camp in the dark, but not use the car battery to power the lights when doing so.
Does anyone have any ideas on a way to wire the ditch lights to function from the car battery and be switched to run solely from the power station? I sketched up an idea using a DPDT switch, but no relays are involved, so heavy wiring would likely be needed. For reference, the ditch lights would be a pair of Diode Dynamics SSc2’s.