Concerned about Brumation

My Beardie Spyro is about 8 months old, we were told he was 4 months old when buying him 4 months ago lol. The last week or two he has been sitting under cover in the position shown in the image a lot more often, and rarely basking, and today I have noticed him sleeping occasionally under there. I believe he’s too young to be brumating but it did start around the time it got very cold here in the UK. He is still eating fine when I take him out for crix and he is eating his greens, and pooping roughly every two days. Do you think he is brumating and if so what should I do?!

That doesn't sound like a full brumation (he would lose his appetite almost completely). Since it corresponds with a weather change, which they can be sensitive to, it may just be a slowdown from that which isn't unheard of. It's good that he is active and eating when you take him out. If everything else is OK I would keep your lights on a usual (long) daylight cycle and keep the temps in the tank up to their normal levels. Track his weight to make sure that is remaining stable. Look for signs of illness such as a dark black beard. Otherwise I'd let him sleep if that's what he wants to do.

Cooper is a serious Beardie expert,so it is always good advice,from him.
I would not want my boy to brumate before age of one year. I live in SD, where weather gets quire cold, and Dezi slows down during cooler climate changes. I make sure he is getting plenty of heat--mid seventy (degrees) at night, and a basking spot around 105. If he is hiding under a cool place, I remove that, to ensure he keeps warm. I also take him out to play, walk about, and get him moving. He likes to chase a cat toy that is basically a stick with feathers on one end, and also a little red "laser" light that I found in the cat toy department. Lots of hugs, tickles and brushing with a soft make up brush also keep him more alert,when he tries to brumate.

I do not allow my boy (age three years) to brumate; that is a personal decision, and there is plenty of info that is both for, and against it. My boy is quite healthy, so has not shown any signs of harm from lack of brumation. In the wild, they must brumate due to cold weather and lack of food available, but it can be a strain on their health, if they are in a weakened position, or do not have enough fat stores. It should not be a problem if they are in good health. I am selfish in that I want to interact with my boy every day, and do not want to be apart from his company during a long brumation. It is not dangerous to them, to keep them active and not allow brumation, so I would say it is a matter of personal choice.