Your dealer should just re-order the car at the new price, it’s a paper based exercise and doesn’t cost them anything or affect the order with the factory. However, there have been a few dealers who won’t do this.
Ask them before you go away, if they say they won’t you can cancel the order at any time and look for another dealer.
Please excuse spelling/typos. Apart from being a clot it turns out I had one on my cerebellum that's now causing various problems!