I drove the Yukon XL around for awhile to try and get the coolant leak to show itself.
Sat under it for about half an hour and nothing. Came back out later and took a peak under and saw it dripping.
It was definitely coming from the front of the engine, but I could just not make out from where exactly cause of a bunch of crap in the way. Grabbed my sony actioncam and shoved it up there while having it display on my phone.
Success! Looks like the gasket failed on the water pump. I’m gonna replace the entire thing though since I’ll be in there. Might as well do the belt and thermostat while I’m at it.