Usually those folks who plant potted plants the following year are in much warmer climates it is difficult to over winter daylilies in pots in very cold climates. I also get some new costly introductions each year and they are all planted directly in my garden. I do pay attention to the parents of new intros it gives me a good idea as to which should do fine here in the north, also inquire of the hybridizer if they think they will handle northern winters. One spring I did pot up all my spring orders for a couple of months then planted in the garden, it did not seem to make a big difference in growth. When I started out in daylilies I planted lots of older cheaper cultivars until I had some experience growing them, then I slowly started adding newer cultivars. Also I have a friend that has a AHS display garden she is a very good source for information on which will do well in our area as she constantly adds new plants from across the country.
Look for display gardens in your area visit and see what daylilies do well in your area. Here is a list of display gardens in your region from the AHS website.
http://www.daylilies.org/AHSre... I would also join the AHS for even more information and quarterly magazines.