I would put them deep enough to cover the cotyledons. The plant will send out new roots on that newly buried portion of the stem to further enhance the root system.
So now you have a variety of opinions, do as you please. I don't think there is a wrong answer here. The most important thing is a bigger pot.
Gardening at 5000 feet elevation, zone 4/5 Northern Utah, Frost free from May 25 to September 8 +/-