Unless there's a time crunch, my 2-cents is wait until the dandelions start blooming. Right now they are under stress looking for food and the queen may just now be starting to lay eggs. If you get them when there's a small nectar flow on they'll be more docile and focused on the young. They'll also have a better chance of surviving as they'll have some newly emerged bees to carry the load during the transition period instead of overwintered bees.
Again just my 2-cents, and I may be overcharging.