You'll need more width than depth. 11' wide will give you just under 2' on each side to load the barbell. You could shrink that down to 10' but that's pretty tight.
Depth could be as little as 6' with half of that for the rack and half for a deadlift platform. You could also deadlift inside the rack and make it really compact. The back uprights on the rack can be used for plate storage so you could do without a plate tree.
Get out the tape measure.