Alternative strategies
You are not alone! I had 8 of 10 colonies survive the winter but I had to recommence feeding in spring and right through the rape season as the appalling weather prevented normal foraging and none of the colonies built up bee numbers. I routinely monitor for potential swarms but due to depleted numbers there was no overcrowding and I was complacent. My main concern was keeping the colonies viable, fed and dry. Nevertheless in June every one of the hives swarmed. If there was a two hour break in the rain one of the hives would be in the process of swarming. It was as if the weather panicked them. Sadly, one swarm drowned overnight clinging to a branch 30 feet above its own hive.
On inspection five had queen cells but three did not. All were left severely depleted.
Two of the hives are now light but back to normal in terms of eggs and brood.
The three without queen cells are now without any brood or eggs. As there is no sign, so far as I can see, of a queen I have concluded these are Q- and as there is a total lack of all stages of brood this has been the case for over 3 weeks. To raise a new queen to start of laying from an egg would take up to about 4 weeks ie to late July. Its first eggs would mature into worker bees in mid to late August while meanwhile the colonies would be shrinking due to attrition. For this reason, In the case of two of these hives, I am introducing mated queens from Romania from a trusted supplier (Becky’s B******z). The other has been topped up with a small swarm that conveniently arrived in my apiary today.
In another hive I have at least found the queen so it wasn’t drowned on its mating flight, if it had one. I am going to observe but have no plan for further action apart from feeding until/unless no eggs appear over the next 2 weeks in which case I will remove the queen to a nucleus box and combine the colony with a queen right hive.
One hive has a number of queen cells not yet emerged and the other has empty queen cells. As there are no eggs and no queens found (though the latter could be quicker than the beekeeper), a queen cell will be transplanted to the hive that has empty cells though there is a slight risk it will be destroyed if a queen is present or a swarm may ensue. This assumes the queens haven’t emerged during tonight. They will be monitored to ensure egg laying starts within 2 weeks of emergence.
I mention all this because it illustrates most of the choices you might consider and because I want to moan about how awful this year is for bees and their servants. I hope it helps.