with my long arm i can comfortably quilt a quilt about 110" wide= i have done a couple that were 120" wide- but i had to do it all the way down 7/8 of it then unload-turn-reload and do the last strip-
check with the quilter you would like to use and see what her (comfort zone is)
when i make king quilts i make them usually about 112"x 120"