Fast way to see, do your bees need feeding is to open inner cover and look,
if you see capped honey combs. It they have, let them be in rest.
Wain feeding at winter only disturbs them.
In September I give winter food for hives and it is enough for 8 months.
I do not worry, do they have food because I know that 20 kg sugar is enough. After cleansing flight I check with hand how heavy hives are. If they are light, I open inner cover and look the situation. Often food stores are in lower box and I feel it with hand.
It is not true that bees consume during warm winter more food. Only brooding consumes when it starts.
We have mild winter too and I know that bees are fine. Now we have only -8C.
If you start too soon they will start brooding up and then if it turns cold the brood will dieThis is a good advice