2016 Explorer Mysterious Coolant Leak

[Steve8316]

I'm wondering if it lost most/all of the oil since the whole front crossmember was coated (just like in the image the OP shared).
...and I would imagine it would take several ounces to coat the frame and leave a few spots on my driveway as well.

It takes less than 1oz to do all that. Try it with a teaspoon of common cooking/vegetable oil (non-toxic, inexpensive).

I read that the compressor only holds around 8 oz. of oil...

The compressor doesn't "hold" any oil. The oil in the refrigerant system circulates with the refrigerant, so it flows everywhere inside. The quantity is usually printed on a label under the hood with other refrigerant info.

Going to order the hose and take it over to my mechanic to evacuate, replace hose, add oil, and recharge the system.

There is no advantage to replacing it now. You can wait until the refrigerant pressure gets too low for the A/C to come on, and then get the hose replaced. That might take years.