For land transport, the typical solution is supply dumps over a large number of partial trips. Your caravan has a max range of N days; you instead go N/3 days,

For land transport, the typical solution is supply dumps over a large number of partial trips. Your caravan has a max range of N days; you instead go N/3 days, drop 1/3 of your supplies, and then return. Do that twice. For your third trip, you can load up your caravan, travel N/3 days to your supply dump, and reload using half the cached supplies. Now you travel another N/3 days, drop 1/3 of your load, and then return, stopping for the cached supplies again on the return. You still consume increasing amounts of resources, but unlike rockets or boats you don't have to carry them all from the start.