There is no way to guarantee ANYTHING. Some shows have closed with only a few weeks notice. Others have given a date only to extend.....or even cut even shorter.
Given the current economy and sales: I don't think either Hairspray OR Spamalot will extend...but you never know.
Trying to plan that far out is difficult....you just don't know when announcements will happen.
If we're not having fun, then why are we doing it?
These are DISCUSSION boards, not mutual admiration boards. Discussion only occurs when we are willing to hear what others are thinking, regardless of whether it is alignment to our own thoughts.