With a spark plug missing, you are sucking unfiltered (dirty) air from the engine compartment into the cylinder with every power stroke. Not a good option, but, if you have to get home or to a repair facility, . . . . it may be the only option.
A little off topic but, . . . years ago there was a "compression release" craze for dirt/racing/off road bikes. The lever/cable controlled valve vented the combustion chamber gasses to induce engine braking. It worked really well, until after a weekend of desert riding, you pulled your cylinder head and saw the damage done from all the ingested dirt. That's when mine went into the circular file. (and I rebuilt the top end) The brakes seemed to work just fine after that.
Anyway, don't wait too long to get those stripped spark plug threads fixed.
Chum lee