I'd think so by I'm not sure... you can try it and see if there's an error message.
I'm assumining these are broken down into different segments that you'll send different regional invites to? Should work if you add that condition into the filter. Another thing you may want to consider though (if you will be doing this more than just this once) is to make a segmentation in the Lead Database with these different segments so you can easily pull them in each time.
We have a similar situation for sales territories and listed out a full listing of the zip codes applicable. We did not push the limit to 6,000 but certainly had criteria listing 3,000-3,500. Unfortunately, Marketo can't do ranges, so listing all of those applicable works just as well. Good luck.