Don't do any fiddling. "Cold" doesn't mean "it has been in the icebox", it means "it hasn't been driven yet today". Instead, consult the tire manufacturers' advice, such as may be found at
http://www.goodyear.com/rv/tirecare/inflation.htm
They specifically say
"Tire pressure should be checked cold, or before you have driven that day, as tire pressure ratings have been designed with typical running heat/pressure build-up in mind."
and
"Don't bleed air from warm tires to reduce pressure buildup."
If they are inflated to 50 psi at the beginning of the day, then you need do nothing more.
Bill