I've moved across country for days with snakes separately cloth-bagged & sharing "ice chests" (no ice, duh- just for insulation) with no trouble. However, none of them were newly-acquired or young- & none needed higher temps. (like BPs) to stay healthy. Since your snake is still "settling in" & you are also new to keeping snakes, I'm not sure this would be a good idea for you & yours.
It really depends on your skills & planning, to ensure his temps. & sense of security aren't adversely affected.
Remind me (us), how many times has he eaten for you so far? Any difficulties feeding? I don't blame you for wanting to combine the trips, but this could backfire, or it may not...I have no "crystal ball" to foresee the future.