Define "stupidly huge".
457m according to the Bluray vs the 285m TOS Enterprise.
If these people can build the STIII spacedock, I think they can build spaceships any damn size they want to.
Personally I see the TOS Enterprise as a 23rd century Intrepid-class equivelent, and Kelvin, Newton, and nuEnterprise as 23c versions of bigger classes like the Nebula, Soverign and Galaxy. We just "never saw the others until now"* (excepting nuEnterprise which was, erm, nu)
As far as I can tell, there's not a single thing Enterprise-D can do that Voyager can't.
*standard Trekkie rationalization since the Klingons grew bumpy heads in 1979.