When a receiver craps out, there is no telling how the servos attached to it will react. Worst case would be an aileron and an elevator at non-zero positions. Successful control using the other receiver would be impossible.
Your best bet short of some pretty sophisticated electronic circuitry is to use a six volt, 2400mAh NiMH or LiFe battery pack and a single receiver. If you are interested in sophistication (which would be appropriate for a two or three thousand dollar plane), I can provide a few circuits for you to peruse. I (and I suspect other hobbyists) don’t recommend it for the Nieuport.
Jim B.