Is it possible to shorten the Ikea Pax sliding door wardrobe?

What speaks against, as you intended, halving the doors and then simply installing the normal door hinges? For that, you would only need to precisely pre-drill the corresponding screw holes in the appropriate thickness as well as the round recesses for the hinge head; for that, you need a router or a hole saw and a chisel. And if you have drawers, you have to check if they would hit the hinges. In that case, move either the drawers or the hinges. Or completely move away from Ikea and get brackets/hinges from the hardware store and use those instead.