The historical sufficiency for a National was a completely full deep brood box for over-wintering. Weighing by just raising each side with weighing scales is perfectly adequate. I used to quietly remove the roof first, as the weight is that much less without it.
A 14 x 12 brood box usually contains far more stores than needed, requiring extra brood frames added in place of unused stores when brooding gets going well.
Only weighing at one end of the hive is dangerous territory. If all the stores from one end is used up, the next time the hive is weighed could be misleading.
As for transparent cover boards, they are simply not necessary and only encourage interfering with the cluster, in winter, by inexperienced beeks.
April is far too late for first inspections if the weather is good for the bees. I leave them alone over winter until mid/late February and then only to observe if brooding is occurring.
When I used to encourage early brooding to be ready for the earliest OSR, the bees were fed with 1:1 at this time, reducing to almost water if stores were plentiful. There is no hard and fast rules as it all depends on the beekeeper’s observational and skills. Once accelerated, the bees must be kept well fed to maintain the heavy brooding and expanding hive population.
Isolation starvation is a problem if the cluster moves away from stores and is then separated from those stores by a cold snap. Following where the cluster is located, and moving, during the winter is easy enough without opening the hive, for those with only a few colonies.
Beekeeping does not stop during the winter - it just needs observations of weather, bee activity, stores, etc. No need to keep disturbing them during their time of slumber.
Polyhives are easier to manage in the winter, I have found. Simply because they do not consume as much stores while clustered.
RAB
