What do we need/how do we find out how many days we have left on park hopper plus passes we purchased and used with a stay back in 2000? Do we just bring the room cards we used back then?
Yes, bring them with you. The only way you can find out what's left is to have them scanned at WDW. This can be done at any Guest Relations location at the parks & DTD, Guest Services location at the resorts, or at the resort front desk.