BTDT, like flying a rudder only thermal glider on a buddy box with a student. Needs a very stable craft, a huge site and very calm day to be successful. You COULD increase the throws, but imho that's cheating.
An efficient well set up & stable plane can easily be flown on the trims but all you will be able to do is to fly gently around on a particularly calm day.
This electric plane was actually designed to do it but primarily to reduce control movement to a minimum to save power.
On a powered flight (no soaring) of a couple of hours the energy used by the servos starts to become significant.