Make them anyway, just make more! Your border will just be a little narrower, that's all.
Formula for making half square triangles from 2 squares:
FINISHED SIZE DESIRED + 1/2" (Seam Allowance) + 3/8" for Diagonal Seam = SIZE OF SQUARES TO CUT
EX: Finished Size 2" + .5 + .375 = 2.875" or 2-7/8" squares
I always round up 1/8" from that dimension anyway, so I don't really need this formula - just add 1" to your desired finished size, then trim to the correct size. I only mention the formula, in case you don't want to waste any fabric.