If you could arrange for the entire bottom of the tank to be supported right on on the glass, not just the rim, and you used a patch as large as practically possible, you might get away with it.
A patch as wide as the tank, less an inch on each side, and at least that long.. a big square. Silicone between patch and tank spread as evenly as you can, pressed down evenly and well stuck on, then sealed all around the edges to prevent any chance of catching or cutting yourself when you work with the tank.
If you had a thick piece of plywood underneath the entire base that was well supported itself, it would spread the pressure, and the big patch also would spread the pressure.
But is it worth the risk that it might fail, which is the key thing here ? If it were me I would not do it.