Anytime I'm making pizza outside of the kitchen, I've had a 3/4" marble slab that I use to prepare and dress my pizzas on. It's pretty nice, but it's also super heavy. So for a while I've been on the lookout for something to replace it with. And then recently I came across a very large cutting board from Ikea called the LÄMPLIG ($20 USD). So I grabbed one and tried it out.
I'll throw a little bit of flour on the board, shape my pizza and add toppings, then slide my Roccbox peel under the dough and take it the oven. It couldn't be easier. So if you find yourself in a situation where you don't have a smooth flat surface to prepare your pizzas, I can recommend this board or one similar to it.
1) The LÄMPLIG is also available on Amazon, but at a much higher price.
2) Personally, I think you should always prepare your pizzas on a flat surface that isn't the peel which is taking your pizza to the oven. You avoid issues where your pizza can stick from sitting too long, and it keeps your peel cleaner if you're making multiple pizzas.