@simon Thank you for your insights and experience, very much appreciated.
I have 16 eTRVs (Zwave Spirits) and 10 zwave Secure 321.
15 rooms (two radiators in the Lounge)
Also I have 14 Hue Motion/Temp Sensors through cocohue beta App
And I am playing with the Sonoff Temp/Humidity and Motion sensors - directly connected to HE
With the in mind.
I am planning on one Thermostat Controller per Room
And one Thermostat Scheduler per Zone
No Guests in House
Zone 1 - Two bedroom rooms that are unused
Zone 2 - Two Bathrooms unused
Zone 3 - And a reception Room unused
These can all sit at 17c 24/7
EXCEPT when we have guests, then each o the 3 zones above will have different temperature needs.
ie Guest Bedrooms need to be 18c at night and the bathrooms at 22c, the reception room 17c at night 21c during the day.
Zone 4 - Hallway/Landing/WC - only two controllable radiators there - the hallway is not controllable (WC included because despite best efforts the door is always left open 
Zone 5 - Kitchen/Study/Utility
Zone 6 - Lounge
Zone 7 - Master Bedroom
Zone 8 - Master Ensuite
and my Office which I have the radiator turned off - I get too much heat from computers and monitors and vent into the Landing
So will end up with 8 Thermostat Schedulers.
The Hue Motion/Temp sensors are already migrated to HE so using those right now and offsetting temperature readings in the Thermostat Controller (the motion sensors locations are optimised for motion sensing not Temp).
And I can combine and weight the Hue Temp sensors for each zone in the Thermostat Controller.
Does that sound reasonable?
Also, Turning heating on through a Rule is quiet straight forward, If ANY Thermostat Controllers state changes AND ANY of the Thermostat Controllers state is 'heating' turn on the Boiler.
I am finding the turn off more complicated and cumbersome - so would appreciate some advice.
Currently I am using a Rule IF ANY Thermostat Controllers state changes AND ALL Thermostat Controllers state is NOT 'heating' Then turn off boiler
Setting this up is painful for 16 Thermostat Controllers is there a better way?