I live in the Pacific NW in Zone 8, but I can partially answer your questions. In your Zone I would expect that you will get top-kill of everything above ground. Unfortunately, in a hard witner, you may lose the entire plant as you are at the limit of nuda's hardiness. As for growth in height, if the plant survives, it will put up taller culms each year despite the topkill, but it will probably be 3-5 years before you start getting anything approaching 8'. However, if you want some other opinions, I suggest you post in the forums at bambooweb.info where there are more people who grow bamboo in your Zone and can speak from experience, and maybe share tips on winter protection.

One other thing...here is a picture of nuda after the temperature got down to -12F. Obviously, the foliage is gone, but I don't know about the viability of the culms.

Here is a link that might be useful: Nuda in winter

Nuda actually gets leaf burned more than most of my other bamboos despite its hardiness rating even though I have never seen sub-zero temperatures since starting my bamboo career.

Atrovaginata and Parvifolia hold up to the cold around here a lot better and don't require any protection. In zone 5 I think the hardiest bamboos should be able to get much bigger than 8-10ft as long as you tie the culms down to the ground and tarp them, preventing any of the cold dry winds from reaching the foliage. If you are in zone 5a, chances are that your bamboos will top-kill on most winters unless you keep the entire grove tarped or under snow cover. My nuda is potted, but as far as the rate of growth, a 2ft tall well established plant from lets say bamboo gardens will likely grow to around 5-7ft tall on the next shooting season, but it also depends on many variables.

Thanks for all the useful inputs.
I guess in the worst case I can still run the plant as a perennial.