How do I estimate the energy consumption of a ductless mini-split A/C unit?
I doubt that any PV array which would fit on this camper could power this a/c unit. The power consumption of the a/c unit is far above what a small PV array could supply.  Based on my recollection of the circuit requirements of room a/c units rated at 5000 BTU/h, when running, this unit will draw about 10 A at 120 V ac so 1.2 kW continuously.

EDIT

One sees campers with 5000 BTU/h a/c units on top. I have always assumed that these were only for use in campgrounds with electric plug in sites.