You're kidding, right? Are you talking one solid color or some design? If solid color, it would make more sense to go buy a shirt in that color. If a design, it would be nearly impossible to line it up because you'd have to print a dozen sheets and press them one at a time and then try to line up the next one with the design on the shirt. Ah, but you can't see through the paper to see if you're lined up or not! And any breeze (even lowering the heat plate) might cause it to move. Tape would leave a mark.
You need a much larger set up for full coverage printing. Large printer, roll paper, huge press..