Deep-Cut Studios have made up some larger mats for me. These Plains design mats are just over 8' by 6' (2400mm by 1800mm approximate). Instead of a formal grid, these have a very subtle 15cm 'cross' grid, indicated by 25mm crosses at the corner of the squares.
Above is a very poor photo showing the crosses; the color of the mat is washed out but gives an impression of how subtle the crosses are.
Deep-Cut mats are printed on a thin, light cloth which can be washed, ironed, and folded or rolled away for storage. Hills can be placed on top or even, if shallow, underneath. I regularly export worldwide. These mats (along with many other designs) can be found in the BigRedBatShop.