Using Infigo Designer, it is possible to set it up so that if text would originally not fit in a field, it can flow into another field instead of simply not appearing. This is done using the "Manage column flow" found under the Infigo Designer tab, as seen in the screenshot below.

For this example, I set up a simple PDF with three fields:
Original field - This is the field into which I will be inserting the text which does not fit.
Flow to A - This is the field the overflowing text from "Original Field" will flow into.
Flow to B - This is the field which the overflowing text from "Flow to A" will flow into.

When you click "Manage Column Flow..." the following menu will open:

Here you can see a list of all the text fields in the document on the left, as well as any pre-existing flow sequences which have already been made by this function. As this is a brand new PDF, there are no pre-existing flow sequences.
To create one, click on "Start new Text Flow", this will highlight a blank flow base in the second box, as seen below.

On the left, you want to select the field which is meant to start the flow, in this case "Flow From", which is the name I gave to the field "Original Field". After highlighting it, click the ">>" arrow, this will insert it into the "Text Flows" column, setting it as the beginning of the flow sequence.
From here, you need to do the same for the fields the text will flow to. As you can see, the flow will automatically go in the order it was added. However, you can change this by selecting a field in the "Text Flow Sequence:" column and using the "Up" and "Down" buttons below it.

Now that the sequence has been set up, click "OK" and save the PDF. Now, upload it to your storefront so that you can see the results.
Below is a screenshot of the product I uploaded the PDF to, as you can see the fields have retained their default text.

Now, if I fill the field "OriginalField" with too much text for the field size, it will flow into "Flow To A" and then anything which does not fit in this field will flow into "Flow To B".
