Firstly , although the 607 date is certainly open to question , it's complete refutation is not a done deal. Scholar has written extensively on this very point , as have other sites eg ewatchman.
If , however , you take the view that 607 is false and feel this is fatal to JW beliefs , you basically have 2 choices.
1... "Christian" way of life. So you now believe the Trinity is true , immortal soul , Xmas , Easter , numerous other core belies that you were convinced from a study of the scriptures were false , you now have to believe were true.
2.. Secular way of life. Now you have to believe that we all evolved from primeval soup and that God either doesn't exist or is disinterested in mankind. The bible is a load of bunk and we are here for 3 score years and thats it. No purpose , no hope.
Some who post on this site have adopted native American beliefs or worship trees. Have they found a greater truth?
To dismiss JWs over a relatively trivial issue that is still not proven and adopting a completely different belief & worship structure is like divorcing your husband because he came home one night from the pub and (you think) lied about snogging the barmaid and then marrying a serial philanderer , gambler and alcoholic and not believing that your new husband does any of these things. It takes a far greater leap of faith than you would ever have in believing (or at least reluctantly accepting) 607.