Do I need two Smart Thermostats to replace a dual zone (up&downstairs) ‘dumb’ thermostats

I just moved and am trying to work out if I need additional hardware to get tado up and running in the new house. In our previous house (no wired thermostat) we had a tado wireless Smart thermostat, bridge and several vales. In the new house we have dual zone dumb thermostats. Do I need a second smart thermostat to replace the dual zones or can the heating system be reconfigured to a single zone which can be controlled with one smart thermostat and individual vales?