This is a really bad idea. The hotspot was intended to be just that, a hotspot. Not a wide area device. If you can even kludge an amplifier on to it, hotspots don't have all that great of a receiver. So you may be able to make it talk, but it may not hear you very well.
The other thing is, if you do find an amp, like someone else said, it will probably come from China and throw spurs and other IMD products all over the band which will piss off your frequency neighbors.
After all this trouble, in the long run you are better off to just put up a small repeater. You could use a MMDVM modem and a used commercial repeater. You could buy a used Motorola XPR series repeater and just "plug it in". The repeater doesn't need to be a powerhouse. 25 watts or less is all you will need.