Only way is to get more bees
- package bees
- join the tiny colonies.
Then keep the hive in warm box. No mesh floor.
When the colony occupyes one box, then it begins to grow in normal speed.
When the colony has one box of brood, it takes one month that you may add second box.
After next month you have 4-5 boxes. So it goes.
One langstroth box of bees weights 2 kg. The best is 4 kg swarm, which occupyes 2 boxes.
Nuc has such advantage that it is full of brood. It grows rapidly.