Limit to select list submissions

I'm looking to limit how often an item in a webform select list can be chosen. For example, if the form offers users to select one of 5 dates, but there should be a limit to how many people could choose each date.

My thought was to create nodes with title and limit, create a view that shows all nodes with limit > 0, expose them to webform with the Webform views select sandbox (http://drupal.org/sandbox/mrconnerton/1373760) and reduce the limit by one on submission with Webform rules, but it seems a very complicated way of going about it, and I'm not even sure the rules part is possible. What would be a better way of going about this?