Considering the next day numbers I would clean the battery posts, alternator terminals and just keep an eye on it. If the alternator does fail, rather than a hiccup, you can keep the coach going while on the road by running the generator which will cross connect to the chassis 12VDC system and keep the engine running until a replacement can be found.
Replacing is pretty easy maybe an hour job. With a bit of searching for a Ford Commercial Truck service center, any independent place that can handle a F-53 based coach or even a mobile tech along your travel route you can make arrangements for replacement. You could even buy a replacement now (which will guarantee the original will fail) so all you will be looking for is someone with tools and knowledge to swap it out.
The V10 has one wide serpentine belt with an spring load slack adjuster that drives all the engine accessories. If there was a problem with either good possibility you would also overheat or the A/C would be also acting up or the power steering and power brakes would be misbehaving. Power brakes are not vacuum driven but use pressure from the power steering pump to assist with braking.