Yes you can. I Have laminated 46" x 20' and it came out perfect. I do have to tell you that if it is the first time you are working with the big squeegee you might want to practice on smaller stuff first.
When I laminated that 20 foot print I had a lot of practice with the big squeegee.
The best way is to place the laminate flat on the print, peel of about 3 inches of laminate backing and stick that about one inch on the table and one inch on the print. Make sure the laminate is straigth and has no bubbles or wrinkles at the begining. Once you are certain it is straight. Roll the laminate onto the big squeegee and push away.
Since I got mine, our laminator is reserved for print that are 49" and bigger. Everything under that we use the big squeegee and we get a bubble free print evertime.
Also, make sure your table is flat, I mean really flat, the smallest warp or bow can really be a pain.
Check out the youtube videos on how to roll the laminate on the big squeegee.