tachanun in a cong that doesn't say it between Sukkot and cheshvan

Some congregations don’t say tachanun after Sukkot until cheshvan. Would it be better to daven b’yechidus than at such a minyan? What if they probably won’t have a minyan without you? If you do daven with them, should you say tachanun anyway?

Better to daven with the Minyan and not say Tachanun