box width for data validation selection

I have a workbook with multiple sheets. One sheet contains only data with named ranges for various data validation functions. The column containing the data has a width of 15 to show all the characters. The cell that it is going in only has a width of four (it is set to rotate the text vertically so it all displays). The problem is that when the user brings up the list, it is too narrow to display all the data. Is there a way to increase the list box?

Excel 2013 on a PC