This isn't business advice. This is life advice.
Your British IPTV customers will survive one day without you. The streams will work or they won't. Either way, you're not the one who fixes it on December 25th.
Your IPTV reseller panel will be there on December 26th. Set an auto-reply on Christmas Eve: "I'm offline until Dec 26th for the holidays. Your accounts remain active. Happy Christmas." Then turn your phone off.
A boundary story from a reseller in Porthcawl. His first year, he worked Christmas Day. Answered messages while opening presents. His family was upset. His IPTV reseller customers didn't even notice it was Christmas. His second year, he turned his phone off. Zero emergencies. Zero lost customers. His IPTV panel was fine.
Being an IPTV reseller taught him that boundaries make the business sustainable. A British IPTV reseller who takes real holidays lasts for years. The IPTV panel doesn't need you 365 days a year.
That said, warn customers in advance. British IPTV reselling with a clear "I'm offline these dates" message manages expectations. Your IPTV reseller panel will survive your absence.