Mine will be the same at 6’ x 3’. I was thinking of getting hard material but cut in (2) 3’ x 3’ sections. Just so I don’t have to deal with multiples.
I also plan on getting - if possible - a 6 in border across the top and bottom. I did that to the one I made by printing 11 x 14" sheets and taping on posterboard. Makes a nice spot to keep play units and materials, cards, etc.