Can Minoxidil treatment be used short-term if hair loss is temporary and due to stress?

Minoxidil is not for temporary loss.  You need to use minoxidil for 6 to 12 months to see results.  Once you stop using it the hairs you gained will be lost.  This has nothing to do with stress.  Best way to address stress related hair loss is to remove the stress.

Yes you can certainly try this because telogen effluvium your follicles are in a dormant stage and so minoxidil will convert hair follicles to grow and then you can stop it.

The concept of short term treatment makes no sense to me. You should be working with your doctor 

rogaine or minoxidil are FDA approved and recommended to be used to prevent or slow down hair loss.  It rarely is used for the frontal hair line, but there is some improvement  in the crown area.. Once you start you need to stay on it to get any results.. If you are planning to use short term, make sure you reduce the amount gradually.  You can also add vitamins and shampoos and laser comb to your medical regiment. , in some cases your hair loss may become under control.  However the most important issue  is to find the underlying cause for your loss for diagnosis and appropriate ttreatment options. make sure there is no underlying medical problem, and if that is ruled out reduce your stress level, since stress can definitely cause hair loss.