I try to make sure there's only one variable in any testing. Milady says it's the "anal electrical engineer mentality" - but then I remind her that she's an EE too
If you have the "inventory", put an ESC and battery into the "equation" that you know is overkill - run the motor/prop combination up and chack results. Then pick a smaller ESC and battery to work with the amps you recorded. May be hard as you're already at 85A, unless you have a 100A ESC in the parts box. I have a 80A ESC and a pair of 5000mah/3S I use for this type of testing.