Fellowship of the Ring had a Two Towers trailer attached to it after a month or two, IIRC. Avatar got a relatively quick re-release as well. Those would be the two closest precedents I can think of.
As Phonciple pointed out, that (and the increase of 200 screens) only led to a 2.3 mil weekend, and the film still didn't re-enter the top 10.
The Avatar Special Edition Re-release (w/ 9 minutes of extra footage re-edited into the film) happened in August of 2010 (8 months after initial release) and took
12 weeks in 3D and IMAX 3D theaters to make another 10 million.
Seeing as Abrams doesn't like doing Special Edition cuts of his films, and there's another Star Wars movie opening in December anyway, and a Force Awakens re-release anytime during the summer season is going to suffer
pretty steep competition, I'm not seeing a re-release of Force Awakens anytime in 2016 doing much more than 20-30 mil in a limited run
at best. I mean, 20-30 is being really optimistic, too. Titanic's highly successful re-release was helped by the fact it was converted to 3D, the Chinese market, and had been off theater screens for 15 years.
If it's going to make a billion domestic at any point, it'll have to happen in a couple years, when the novelty of being able to see it at the theater returns to such a level that it can maybe feel like an event again, much like the Special Editions did 20 years after Star Wars initially opened.