bearisgray is right. You don't get a bigger quilt unless you add more fabric. You can do this with setting squares or with borders. In Nan's example (not sure how she got the numbers - I don't get the same ones with EQ) the on-point quilt setting of 9 rows by 10 columns is set with 90 9" blocks, but has an additional 72 9" blocks filling in. You can't magically make a bigger quilt out of the same blocks by setting it on point. But I do think that on-point quilts often look more dramatic than straight sets.
See example - this is what EQ means by a 9x10 on-point setting. There are 90 of the blue blocks, another 72 plus setting triangles of the yellow ones.
ETA - I see where Nan got her numbers. EQ automatically adds a 1" border, which you have to remove if you don't want it figured into the size calculation.