In 380 AD/CE, the Byzantine Emperor Theodosius issued The Edict of Thessaloniki which nationalized Christianity within Greece, Asia Minor, Italy, as well as other parts of The Roman Empire, while also ending the centuries old Greco-Roman Olympian religion. The Temples were destroyed, closed or in many cases, converted into Churches. If my memory is correct, theatrical performances at places, such as Epidaurus and Delphi were discontinued and the Olympic Games had also ended under Theodosius' orders. The Christianization of Greece, Asia Minor and the Italian peninsula, also resulted in the discontinuation of Olympianism.
However, is there any textual evidence that proves or is there any plausible/ credible circumstantial evidence which refers to a percentage of Greeks and Romans who practiced their Olympian religion in secret-(literally "behind closed doors") during the 400's AD/CE?-(that is to say between The Edict of Thessaloniki and The Fall of The Roman Empire in 476 AD/CE). In other words, were there any Crypto-Olympian worshipers in Greece, Asia Minor and/or Italy after 380 AD/CE?