Wind: Speed, Direction, and Value. Also, see 'British Wind Rule".
I've seen zero wind conditions out to 1,000 yards, not often but more than once, and guns set on mechanical zero miss at extended distances. The same rifle, set on mechanical zero, hits its mark @ 500 or even 700 yards, but does not hit at 900 or 1,000. Some rifles need wind adjustments dialed-in on the gun, despite the abscense of wind, to establish mechanical zero; especially at longer distances. Bedding has a lot to due with this issue.
As for elevation: @ 1,000 yards, with 308 Fed. GM 175, I have a 6 moa difference from <45 degree F to >95 degree F. In brief, @1,000, if I dial in my winter elevation of 42 moa and what I really needed was a summer 36 moa, then with all else being equal, my two dollar bullet just sailed 60 inches over the target. (6 moa @ 100yrds is 6" of change, right, so 6 moa @1000yrds is 60 inches of change)
It is much eaiser to nail those 1,000 yard targets with a keyboard then it is with a bullet. Have fun.