5k or 10k Service Intervals for Desert Driving?

Question for the experienced members: should I be doing 5,000km or 10,000km oil service intervals if I'm doing desert driving every weekend? My Prado 150 (2.8 diesel) manufacturer spec says 10,000km but I've heard desert driving is hard on engines due to dust ingestion and heat. Worth going to 5k intervals? Also interested in thoughts on air filter service frequency — I feel like every trip the filter is coated in fine red sand.