The Christians and Druids never came into contact with each other. This video describes the last stand of the druids. But not against Christianity. It describes the last stand of Druids against the Pagan Roman empire.
The Druids made a last stand and they were massacred in 60 CE. But they were not massacred by Christians. This invasion was waged by the Pagan Roman Emperor Nero (whom the Christians also see as a villain). The Druids were outlawed by Romans in 43 CE. The Druids became extinct by the 2nd century CE. There was no Christianity in the British Isles during this time. It arrived much later. The druids and the Christians never met each other.
The response of Greco-Roman Pagans to Christianity was very meek. In the first place, the pagans had political power. The mighty Roman emperors were all pagan until Constantine in the 4th century. Yet, in the first three centuries, Christianity not only survived but also thrived. It converted a significant % of the population without political power.
The Serapeum in Alexandria was one of the largest temples. When Christians destroyed it in 392 CE, Greek Pagans of Greece did not feel strongly enough about their Gods to fight for them. They also made no efforts to rebuild the temple. There was no Pan-regional Pagan resistance.
In the 4th century, the Governors, officials & soldiers of the Christian emperors were mostly Pagans. They never attempted to organize a widescale resistance against the emperor. They collaborated with the emperor in the destruction of their own religion for governmental salaries & perks.
Contrast this behavior with that of Kashmiri Hindu Brahmans. When they were given a choice by Sikandar Butshikan to convert or die, many chose the latter option. Most others left the country. Janeu of killed Brahmins was put on display. We don't have a Greco Roman equivalent for this. Hindu temples of Somnath and Eklingji were destroyed several times. They were rebuilt again and again. It is not hard to see why these temples still stand today whereas Serapeum has perished.