I just bought four Nugget rhizomes from Freshops last week. I put them out two days ago in some large pots filled with a topsoil/compost/peat mix with a little Miracle Grow sprinkled in. I put them about an inch under the surface, most vertical, and one horizontal just as an experiment. I too thought about keeping them inside, but decided to put them out in the back yard. We'll see what happens.
I know, I should have done this a couple of months ago, but it just wasn't the time. The price I paid for hops at my LHBS was steep enough that I didn't want to waste a year on getting the bines started. As is, the three rhizomes cost less (at $4 each) than 4 ounces of hop pellets.
I actually bought three rhizomes, and Freshops sent me four! Delivery was quick. I plan to get other varieties next year, but Nugget was all they had left. I'll order from them again!