The nearest watering hole that you know of is the lake in K6. You're in L4 at the moment. The food and water situation is not great. As far as supplies are concerned, "Pack for a few nights camping in the rough and we'll need some extra supplies for my friends and miss Elodie" so you probably have another two days of rations. Water is the sticking point in the desert. Gabriele can find out out which plants will get you water (think cactuses) if you chew them, which will keep you going, although having to stop for that will slow you down. Also resting during the hottest part of the day and only travelling in the morning and evening, although that will also slow you down.