Chainsaws

I'm buying a chainsaw this week. Most likely a Husq or Echo in the 45 to 55cc range with 20" bar. I'll be using it primarily in two locations; one at about 800 ft alt and the other about 3000 ft. What happens if I leave the carb adjustment at factory low altitude settings and use it at 3000 to 3500 ft? Constant back and forth to a dealer for readjustment is a deal breaker. thanks