Is "a solas" only for two people, never three or more?
Déjanos a solas = leave us alone together (the two of us) and Déjanos solos = leave us alone = Déjanos en paz.
But it only works with two people and not more than two right?
2 Answers
Pretty much, it can also work for one: ¨Quiero estar a solas**->I want to be alone.
Your questions are very incisive. Usually, Déjanos a solas o solos involves a couple asking a 3rd person to give them some privacy. However, the way the verb Déjanos (a nosotros) is conjugated, it could be more than 2 people. Logic tells me that it can't be too many people because then that would defeat the purpose of privacy.
Déjanos en paz is perfectly translated as Leave us alone.