Cookie limits?

I’m using Wp-Polls for a site that will have hundreds of polls.

As I’ve set it to use cookies to limit votes to one-per-user, so that users are always aware of what votes they placed – rather than multiple voting, I’m concerned about potential problems when users have completed enough polls to have reached whatever the cookie limit is for their browser and older cookies get deleted.

I realise this may seem (and actually be) relatively minor, but the site strategy is to enable users to always be aware of what votes they placed.

Suggestions appreciated – please/thanks/etc.