Presumably at National Harbor again in 2020. There really isn’t anywhere near D.C. (other than maybe specific precincts) where local politics align with those of CPAC, but P.G. County seems a really unusual choice to host it. (More) Even Anne Arundel Co. makes more sense; presumably it and the Eastern Shore are too far from D.C.?
(Yes, I know it has everything to do with it being where the sufficiently large hotel/conf. center happens to be located.)