Just use the generic he[1]. It's classic and has the benefit of not injecting politics into an unrelated issue.
[1]: https://en.wikipedia.org/wiki/Third-person_pronoun#Generic_h...
[1]: https://en.wikipedia.org/wiki/Third-person_pronoun#Generic_h...
The singular they[1] has precedent going back to the fourteenth century. Just use that.
I wish people who felt about that strongly and wanted to make a political statement just used the gendered she creating the fictional world where only girls exist. That would have been so much simpler and avoided so much pointless arguments over the grammatical number and gender of pronouns.