If the dark energy doesn't rip apart the universe... Which it might do.
Anyways, the galaxy clusters might end up forming supergalaxies, especially the large clusters.
Exactly how large these supergalaxies will be is, ofc, only a question about how big the galaxy cluster is.
If a galaxy cluster is 100 times larger than our Milkyway, then it's possible, if the dark energy doesn't accelerate too fast and the galaxies lose each other's gravity grasp.