45 or 50 blocks? Let's figure 48, which is 6 blocks by 8 blocks. If they are 12" finished, with no sashing, you'll have a quilt 72" BY 96". Add borders, and YES, that is a reasonable sized quilt!!! But I like to set off sampler blocks with a unifying sashing, so maybe I'll end up with another monster...did someone whisper UFO?