The two questions I have is how long can you wait to put them in the ground and why two per pot?
If its only going to be a month yet, you could probably wait. Just wipe the rhizomes with a light bleach solution and store them in the fridge.
It you need to pot them, try to stick to 1 rhizome per pot. If you can't get them in the ground until mid summer, that root mass will be huge and tangled together. So if you have 10 rhizomes now, you are only going to end up with 5 crowns. When I throw them in pots, I only put one and a I make sure the pot is at least 18" in diameter. By the end of the summer, that whole pot is one giant root ball.