I agree you shouldn't try and "shrink" your seam allowances or your points won't look great! Sue has some great tips for adjustment - in your case I would think about adding a "goose" on each side (that will add 1 1/2") then go from there with adjusting to fit. I find, as Sue says, "geese" will stretch a little if needed, as is my case where my quilt is about 1/2" larger then the geese will be. Best of luck!
My quilt centre is 65 inches.
Will I gain enough length, if I shrink my seam allowances when joining the pp strips?
Should I just go with my original thought and do the single seam goose?
Something else entirely?