A 20 meter Ethernet will add less than 1ms latency -- wireless will add far more and be very unreliable in comparison.
In fact, through multiple routers configured as APs and switches, I have a 450 foot run of CAT5e and its latency is still less than 1ms with an SSD to SSD transfer rate over 860Mbps.
Wired crushes wireless for latency and stability.