Many I fear will have this problem as I do, that of very small survivors hanging on grimly. So what can be done to support the weak ones?
You may read here and there to take from the strong to help the weak. A very good way of harming the strong and killing off the weak ones in reality. LEAVE the strong ones alone they too are struggling at this time despite appearances. The weak ones cannot cope with donated brood, it will further stress them and the brood will most likely chill for lack of bees. The only donation that will assist a weak colony is more bees, and how that can be done at this time defeats me, so better to not think of robbing one for the others “benefit” until later in the season.
Talking of later the bees or mine at least are 4-6 weeks behind. Just something to keep in mind when making plans.
I will make up some insulated dummy boards that is a rectangle of insulation jammed inside an empty frame and put that between the bees and the next comb until they are strong enough to cross over the barrier themselves at which point I would move it out one comb. Say the bees are on two frames, have a dummy between them and the hive wall if a timber hive, then the two occupied frames, then the insulated dummy, then the rest of the frames, and work over slowly as the bees increase.
If you have poly nucs you may consider transferring from timber hives into poly nucs until the bees are bursting at the seams and then transfer back to the timber to go on from five frames.
A half feeder of light syrup would assist too, but not a feeder on top please, that is cold work for the colony. A frame feeder is what you want here and now.
I saw evidence today of fresh pollen coming in and already stored so my concerns over that issue are allayed. Provided the weather stays as is for a few more days at least then they should be all right for another week or so if the weather breaks.
I can honestly say though I have never seen such poor over wintering in my years of beekeeping. It’s going to be a struggle to build up the colonies again and nucs are going to be very pricey I imagine.