Sally, the 2 to 3 feet is as much roost space as you will need for your turkeys, regardless of age. I would suggest, as adults, they will need about 9 sf of floor space. Outside space depends on you, the more they have, the more exercise they can get. I free range mine on 5 acres, but pen them up, about 5 to a 10x10 pen, if I want to fatten them up, more than the rest of the flock, a little prior to slaughtering. I have 6 in a pen right now and the last 2 Holland White and BBW Toms, weight over 50 pounds, I guarantee you and are as fat as sumo wrestlers.LOL I don't think they will make it to Thanksgiving, before they are too fat to stand. The pure Holland White Toms in the same pen, on the other hand, are about 35 to 40 pounds at 7 to 8 months. They have also bulked up a lot , now that I have restricted their running,(my birds are too lazy to fly, unless they have to), which they do a lot, with wings flopping, every time they hear anything that may be a feed bag opening.
I have been feeding FF and BOSS, mixed with whole corn, for the last week or so, to finish them up, and they are really coming along nicely. I expect them all to reach somewhere between 40 to 50 pounds at slaughter, around 9 to 10 months old .I will weigh them, after slaughter and let you know, if I can get DH to stand on the scale and hold them in his arms, because I can't lift them, anymore.LOL