Like you, Mick, I'm just on the right side of 80, and yes, I do shut down for the winter months which is when I delve into genealogy.
In respect of heating, my workshop is a garage, and has been left as such firstly because when I'm gone, it will still be a garage, and secondly, I don't think the expense of insulating it is justified at our age. I have therefore, an ancient 1kW convector heater, and a 3kW, with two settings, fan heater, so if necessary I can call upon 4kW of heat. Ok, it's expensive, but so what, I can't take it with me, and in reality, it's only a small amount compared to the really big power users in the house – six storage heaters if we use them all! Plus, of course, the electric hob and the electric double oven.
I should also point out that both the lathe and the milling machine are fitted with some small cabinet heaters to keep them slightly above air temperature thus avoiding condensation and the resultant rusting.
As I'm writing this, I have actually been in earlier this morning and switched on the 1kW convector heater in an attempt to remove some of the cold.
Well, those are my thoughts.
Cheers,
Peter G. Shaw