Our preference may be affected by our weather. Ambient temperature for a typical on-site job here in Georgia is in the high 80s or above, so it's a lot more economical to hold cold meat than it is to cool down hot meat, unless you own an ice company anyway.
That does bring up another good point that most people starting out overlook - your profit is limited by the total of all your costs, not just the obvious ones like meat and labor. All those little items can add up fast!
PS - I hear you on rain; sure hate the weatherman. You can create and even execute the perfect plan but if come the day of an outdoor vending event the weather is lousy you're gonna lose money, period.