Changing master pages for a dynamic fillable form




I have created a form where people are expected to fill it out, save it, and email the pdf to me. The form contains expandable text fields. There are two master pages, with the first being portrait orientation and the second being landscape. There is one page in the middle of the form that is landscape. The problem occurs when data is inputted on the pages prior to the landscape page, and the text fields expand. When the text fields expand they flow onto the landscape page and push the items that were on the landscape page onto a portrait page. Is there a way to have the fields expand and flow so that they remain on portrait oriented pages and not affect the landscape page?