Most of the good camping tips I got were from Mumsnet! I'll try to remember...
Take duvets, sheets and pillows not sleeping bags
Layer a blanket between your mat/air bed and the ground, we always take one of those picnic blankets.
SIMS (self inflating mattress) are your best friend. They are more insulating and comfy than airbeds, get the 10cm width ones
Kids can sit on duvets laid flat on the back seat of the car to save space
Take glow sticks, they're fun and cheerful for when it gets dark. My kids always took a few to bed each night
.....and plenty of wine
Clean socks are warmer than ones worn in the day. Take more socks than you think you'll need
Change into pjs early and put clothes back on top.
Onesies are good as they can play in them before bedtime and stay warm, go to the bathroom etc.
Don't plan to go camping for too many days. 3-4 nights is great
.... buy a wine box and take the silver pouch of wine out, freeze it solid overnight and use it in your cool bag to keep food cool on the first day. Then voila, cold wine for your first night on the campsite 🏕 🥂