OP again .... Also, Mike asked:

However, I would be interested to know if it has an outdoor sensor and if it
works through such things as leaded light windows or the like....

Yes it has an outdoor sensor - that's why I bought it. There's no
reference to such limitations as metallic 'barrier' interference - only
to reinforced concrete, and to other electronic equipment being too
close to the base station.

The handbook is very clear about siting the sensor and the base station
-- obviously because the manufacturers must get complaints about these
things being "faulty" when it's just that too much has been asked of
them. Has to be said - most of what they tell you is pretty
common-sensical.

John