sure lots of times- usually my (problem) is opposite from yours- often the quilt is wide enough- but needs more length. but either way- i've added a row of blocks to each side which is not on top and bottom- then borders to add width- i've made 8" wide borders on 2 sides and 4" on top/bottom=
what ever works and looks (right) to me.
it is your project- you can make it any way you want.