My wb runs very cold or just off the blue all the time, when i got it i took the radiator out had it cleaned and pressure tested flushed the block backwards and fowards by removing the thermostate, also tested it in a saucepan with a temp guage, it runs the original clutch fan and shround, 45 deg days are no problem even in traffic.
my cobra runs twin thermos, as the clutch fan set up would be to far away from the radiator, but i have done the same to it, the thermos kick in at about 89degs in traffic and can keep it there while sitting around.