Singular they always gets me confused about how many people we're talking about. As a non-native speaker, I wouldn't call this solution perfectly good.
On the other hand, I think it's an advantage that plurality is ambiguous. You can always make the plurality certain with additional words and when it is necessarily, and e.g. "you" is already a pronoun that has ambiguous plurality.
I assume that your native tongue is one where pronouns necessarily indicate plurality, and also that your English education almost always uses they to indicate the plural. But there are languages that have independent subject pronouns that do not mark for plurality; they indicate plurality when necessary with other words.
I assume that your native tongue is one where pronouns necessarily indicate plurality, and also that your English education almost always uses they to indicate the plural. But there are languages that have independent subject pronouns that do not mark for plurality; they indicate plurality when necessary with other words.