I am going to attempt to cover an 18x24 slab cake with red fondant. Does anyone have any suggestions as to how I can cover it all in one shot, I really don't want to do it in 2 pieces. I am just trying to figure out what the easiest way would be and if anyone has ever done that

I use an empty cardboard wrapping paper roll, the really long ones from Christmas paper. Roll the fondant as normal and then roll it up onto the tube , you'll have lots of room for your hands to unroll it onto the cake. HTH

I have a 2" diameter x 18" dowel I bought from the Home Depot. It rolls the fondant out well and I use it to pick up the fondant.