You should be fine running without the anode rod for a couple week long trip. The rod is there for the "long term" protection of the hot water tank (i.e. minerals attack the rod and not the tank). Doubt if running two weeks without an anode rod is going to make much of a difference in the long run.
Make sure you take some RV Antifreeze with you so that you can re-winterize your rig for the return trip. Things can freeze up pretty quick at 65 mph.
Also, 12 volt furnace
use ... if it's relatively mild, and you only run a couple of cycles at night and a couple in the morning ... you should be able to go a couple of days easy.
But if it's cold, and the furnace
is cycling on and off all night ... it will drain the trailer battery