When you have to tune engines because the weather changes from day-to-day, expect to have to adjust them when you make a significant change in field elevation. I've had to re-tune engines on the same day, when the day changed from cool in the morning to hot and humid in the afternoon. There is no such thing as a "set and forget" engine. To keep it operating properly, the tuning will have to be checked before every flying session, and from time-to-time during the flying session to make sure nothing's changed. That doesn't mean you 'tweak' the needle every time, but you still need to keep on top of things.

When you move from a 500-foot field elevation to a 2000-foot field elevation, you WILL have to reset your engine. It will wind up with the needles turned in a bit because the air will be a little bit thinner, which means less fuel will be needed to make the proper fuel/air ratio. Less fuel going through the engine means less power, so expect a slight power loss. It may even be noticeable.