Bee empire growing

I was thinking of raising my own queen but if you think 1 hive isn’t enough then I am reconsidering.

The only problem I have is that I am happy with my bees, they are friendly so what ever bloodline they got I want to keep.

I suppose I could order a queen for my new hive, keep my old queen till next year. Then sadly kill that queen and let them raise there own queen in the old hive so this hopefully keeps some of the bloodline in the bees. As the drones from old hive will mate with the new raised queen?

Is there a better method of keeping my queens genes?