We don't need a big crunch though, if the universe's dimensions collapse as it gets smaller, gravity no longer becomes an attractive force and the universe simply reinflates. Cyclic model has something going for it with the cosmological constant, and the fact that dark energy can use the universe to come back empty without violating thermodynamics laws.That would be nice but don't keep your hopes up.
The Big Crunch is inconsistent with available data. According to the best model we have, accelerating expansion will take over as the cosmological constant dominates the universe's energy density.
We don't even need FTL we just need to make wormholes so the distance from here to there gets shorter