I generally have good success running an inch more pitch on the prop and a couple of extra cells in the battery. The good thing is that electrics don't lose power at alititude. Keep it light. Beware of the small aerobatic electrics under 200 sq inches of wing area. (The Crazy Max does fly well.) People have a lot of problems flying them well up here especially in the summer. This is only at 4200 feet, about 1000 beleow where you are. A lot of times the manufacturer will recommend a bigger motor and battery pack for higher altitude flying. By the time all that is done the wing loading approaches that of a 40 size trainer and turns into a snappy dog of a plane. I've flown a couple of electrics at 7200 feet. They do become a bit sluggish in the air compared to lower altitudes, but they do fly.

If it says 6 cells with 6 inches of pitch, go 8 cells with 7 inches of pitch. Ofcourse, experimentation is the best way to get the plane flying.

I once asked a Global / Hobby People tech about what their definition of high altitude flying was. He responded 4000 feet in cool air is their definition. Well, I live at 4200 feet and the density altitude gets up around 7000 feet during the summer. I also fly at a field at 7200 feet where the density altitude soars to 10,000 feet during the summer.

I'm sure that someone will disagree with what I have said.