Second Winter with my BTS and im a bit worried

[DracoDussumieri]

Hello,

this is the second winter since I got my eastern bts. It is in good condition was very active in the last months and ate well.
Now temperatures rapidly dropped here in Germany and I could not keep my room temperatures consistently high. Therefore temperatures in the enclosure also dropped lower during the night to around 14 degrees Celsius (57,2 fahrenheit). During the Day when the Lamps are on temperatures go up again to the normal 20-23 degrees celsius (~69,8 Fahrenheit) on the cold side of the enclosure.

The skink became very inactive, it stays burrowed all day and hasn't eaten in over a week. Did the temperature drop trigger brumation? Should I be worried? Should I change my daytime and warmth settings now? Currently, the Heatlamps run for 11 hours a day. Should I keep offering food every 3 Days (it hasn't touched the last 2 portions).

Originally I did not plan to trigger brumation since I read that if you don't plan to breed it is safer to simply keep the temperature consistent throughout the year.

Thanks in advance and happy holidays to you!