IMO, the Creedmoor is fine for 600 yard matches with the 120-130 gr bullets, but for 1,000. Will it work? Yes. Best solution ballistically? No.
I prefer the 139 Scenar and 142 SMK at 2950 fps which the Creedmoor will not achieve, the case simply isn't large enough. Problem with a 140 gr class bullet at 2950 fps is that any cartridge capable of reaching that velocity is very hard on barrels given a 20 round string.
If you want to shoot at 1,000 you might consider the 6mm BR or one of the variants such as the BRX or Dasher. The 6 X 47 (based on the 6.5 X 47 Lapua) might do well too, low recoil, excellent ballistics. They would all fit in a short action nicely too.
The problem with 1,000 yards is everything is a trade off. Ballistics rule and things like the 6.5 X 284 have low recoil and achieve good ballistics at the expense of barrel life, while larger cailibers achieve the same or better ballistics and better barrel life (sometimes) at the expense of greater recoil.
Given the expense of an accurate build, a lot of research is nice. You might try the 6mmBR.com website, they have a fair number of good articles on long rnage shooting and cartridges for openners. Also links to toher sites such as F-class and highpower.