If I buy a Zone 1-3 Paris Visite pass and want to travel to Zone 5 can I pay the difference? We want to travel to Chateau de Vaux-le-Vicomte but this will be our only Zone 5 excursion. Can I just pay the difference or buy a zone 3 to zone 5 ticket?
Paying the difference beyond your zone coverage is only available on Navigo passes, not the Paris Visite.
You could theoretically take a train till some station within Zone 3, disembark, exit the turnstiles/gates, return to the ticket office or vending machines, and purchase single-use return tickets towards Vaux-le-Vicomte from whatever station you're at currently. With this plan, you'd have to use the RER D train (slower, more stops) from Gare de Lyon, stopping at Créteil-Pompadour, then reembarking from there till Melun and completing your trip by bus (line #36; There's no direct train to Vaux-le-Vicomte so a bus is required in any case).
The less complicated option is to purchase single use train tickets to and from Gare de Lyon to Melun, then completing the trip by bus #36 to Vaux-le-Vicomte for that trip.
There's also a shuttle bus (10/5€ adult/child, return) from Verneuil l'Etang to Chateau Vaux-le-Vicomte. You'd start this journey from Gare de l'Est taking Transilien P train till Verneuil l'Etang then paying (cash only) to the shuttle bus.