Realistically speaking, no.
With the newly announced Flash/Supergirl crossover coming in March (which I'm sure everyone is excited about) fans are wondering if there are any other areas where the TV shows can cross over. I mean sure, there's the potential movie crossovers (Crisis on Infinite Earths, please) but with Supergirl finally in on the action, theres not much left that can be done. With the Titans show officially dead in the water, the only other DC shows on right now are iZombie, Gotham, and Lucifer. Whether it be the amount of realism or just the tone of the show, none of those really seem like they have any crossover capability. iZombie, even being on the same network as Arrow and The Flash, seems like it was designed to be standalone. It looks as though any more crossovers will have to wait until a new show comes along