In the colder weather keep your mags in your pockets to keep the gas warmer when not in use. That's about all I change when pistol only in colder weather. Or just buy an aep, but you'll be very outclassed by pretty much everyone else at the site.
Otherwise just make sure your hop up is properly set for whatever BB weight you intend to use - you're already at a disadvantage in woodlands so you seriously need to get whatever range increases you can.
Pistol only is a lot of fun to do, just make sure you know your weapon's capabilities (range, fps, accuracy, reliability, etc.) or you will have a bad time of it.