If a beekeeper lost a high % of colonies over this last winter then there must a serious underlying cause. Varroa or Nosema are usually the most likely causes of losses along with drone layers.
The issue of winter losses this year seems to have a major geographic ingredient to it. Some areas report very low losses this winter. Other places reporting loss levels that are average to above average. It seems mainly down to what weather they met in August and September, and effectiveness of varroa control.
However, it is still way too early in much of the country for most of us to start crowing about low losses. In my part of the world the small ones will still be petering out for at least another month, and that is before we even get into them to see what is a drone layer or queenless.
FWIW we are expecting to have 20 to 25% losses in both types of wooden hives (Smith and Langstroth), but a lot of the survivors will need a lot of help. Three weeks of weather chaos in August after Hurricane Bertha, plus worse than we would like varroa problems, and a touch of N. ceranae, all went into a mix that put too many colonies into the winter with not enough young bees, and in some cases those young bees had been affected by varroa.
Some apiaries will be 50%, others that were further away from the adverse weather in August will be far less. The poly apiaries have losses that are negligible, probably 5% and most of that will be queen issues though a FEW colonies have dysentery visible too.
So.....it will be a good winter for much of the UK with some less fortunate areas.
However......if all I had used to control varroa last year (and it was a higher levels of varroa season in most parts compared to recent years) was icing sugar dustings I would be expecting to have very few colonies left in many apiaries this spring.
ps. We have plenty of those people up here too who seem to have lower losses than everyone each year, even no losses at all, for improbably long periods. Either they are far better beekeepers than we are, or they are lucky, or its all political (either on a micro or macro scale). Funny how they seem to have plenty gear around for making splits and doing swarm control the next season......................