I think there may be confusion between measurements and fittings. The tailors take a single set of measurements, though they often will remeasure you on subsequent annual visits, say, but the better tailors really need multiple fittings as the garment reaches degrees of completion.

Even with a tailor that's done multiple suits for you, you should count on several fittings to get a decent fit. I think I had 4 last time and this was after several suits from my tailor, W W Chan in TST.

W W Chan visits NYC twice a year, I believe. You may want to go by a couple of the places recommended in this thread to discuss your time constraint.