The LC300 with 110l should be fine, but yes if you can bring an extra jerrycan that would be great.
Regarding the food:
1. Lunch we can take from the ADNOC nearby Masafi Friday market. At least that's my plan. However anything is possible and there could be certain closure times for National Day, hence i would recommend to pack sandwiches and some snacks as well.
2. Dinner Day 1 we will be not too far away from an ADNOC: https://maps.app.goo.gl/9XqFihDK5fukrLZC8 approx 10mins drive. Based on the time we arrive there we can either first drive to the ADNOC together and then make our way to the camp site. (yellow marked area is camp site)
3. Breakfast day two. Better take some snacks, croissants, from the ADNOC the evening before.
4. Lunch Day two we should hopefully reach Faqa (Dubai) which also has an ADNOC.
5. Reaching our end destination by 3-4pm in Ajban INSHALLAH