You definitely can copy a suit and I think they can get it close to the dimensions you want, but the materials used (interfacing, shoulder pads, wool etc) may mean that it may not fit or drape the same.
They have been instances where a tailor who has the pattern of an existing client stored, was not able to cut the same suit because of the material used. Also copying a suit seems to me a lot more complicated that doing it for a shirt.
Remote MTM on a suit is a lot riskier than shirts. Even TAT who churns a decent suit, have been known at times to screw up. Many a time, the end product of remote MTM will require it to be tweaked again by a local tailor.