I've got a large sulcata (over 90 pounds) that's outdoors 24/7/365
I'm in NC. He has a large heated building (ceramic heater on a
thermostat and a hot air blower for nights) days there are
160 watt Active UV lamps and 150 watt garage lights on a screen
in one section of his cottage.
As to Africa and survival, you must realize that the sulcatas
there burrow and the temps in the burrows and ground temperature
isn't going to drop like the air temp does. I would NOT allow
my sulcata to remain outdoors in cold temps unprotected without
a heat source, when mine was a little tiny guy he would choose
to sleep at about 78 degrees, and not until he was bigger did
he sleep at room temp indoors, now that he's outside I wouldn't
allow him to get below 65, as a matter of fact I'm not comfortable
suggesting that even though I've read it, my own sulcata will have
a min. of 70 at the COLDEST. 75 sounds more like his sleeping
area temp. His basking temps are 110-125 F.
I can't wait for summer again, hate this weather!
Some of my pics on my site have faded off, due to my neglect,
but you may find something to give you an idea on the Tortoise
site below. Take care, niki
Teddy
