I agree whole heartedly with Just_Plain_nuts. the current location of the species needs to be considered.
I have a Brissie coastal and 5 Darwins, all fit and healty living in the chilly adelaide hills, and yes we get nice cold nights just like canberra, but no snow yet. I have the Coastal in a huge enclosure, masses of ventilation including a full steel mesh roof, that i partly cover with coreflute in the midst of winter, but his heating is a 25watt heat cord with a hide over it. 2years he's been in that enclosure, and has grown 4 ft (1.2m) in that time, I just made sure the temp in the hide wasnt hot enough to burn. I leave it running 24/7 and he comes and goes from his hide, he even curls up alongside the mesh on the floor when you'd think that would be the last place he'd be (i put a thermometer the room side of the mesh one night, it was 15c and he was less than 2cm from the probe ! !
He eats regularly, sheds well, but by all ''standards'' his enclosure is wrong, wrong, wrong ! ! Way too much ventilation, no humidity control, no strict 10c temperature difference between the hot and cool end...... yet he carries on regardless
and no !... his human co habitants dont run artificial heating/cooling a great deal, if i'm cold i throw a jumper on, if i'm hot i'll take the jumper off LOL.
my 5 Darwins are still in small enclosures, but even then i have managed to maintain a range of temps...and the adult enclosures will be set up with the same 'one optimamal hot spot' as above.
like others i've often scratched my head thinking 'in the wild they wouldnt have only a 10c temp gradient' so i deliberately set out to give them ONE optimum hot spot. and thats all they get, the rest of the temps fall where they may. Yes i think some people get too caught up in the 'must be XYZ' otherwise you are a bad keeper...... rubbish, i have another theory too..... if we keep our reptiles always at that 'optimal' temp range, then what happens when the power cuts out..... what happens when we have heat waves.... are we starting down the path of creating 'princess pythons' that get RI and regurgitate their food when ever the temp gets one or two degrees either side of 'perfect' ????