While I personally think fluoridation provides a net public health benefit, people can choose to ingest less if they so desire (provided that they are not harming the health of themselves or their families).

In areas where naturally occurring fluoride levels are too high, an "activated alumina defluoridation filter" is used. This is not a portable solution.

As I understand it, reverse osmosis removes a large percentage of fluoride. And just about every grocery store has a fill-your-own-jug unit. So, for a traveller, filling a few handy-sized jugs for drinking and making tea would be pretty easy.