Number of team members per grid row

Hi. I am trying to accommodate for long 'Member Positions' by changing the number of team members displayed per grid row. Don't want to the 'Member Position' values to wrap. Tried setting the Posts Per Page parameter on Query Member tab to something less than 5 such as 3, but that limits the number of members displayed to 3 and doesn't utilize the full width of the screen. If I set this back to -1, it displays all 45 of my members but only at 5 members per grid row. How can I display all team members, but at 3 to a row utilizing the entire width available?