We have all come to these cross roads and have had to make hard decisions, I admire your 'courage' in the face of so much hostility. Its so clear isn't it, that its a cult!
I personally didn't want a confrontation with my aging mother or In laws, they are fanatical to say the least. Every sentence is marinaded with nuances of the 'Cult'. I never really noticed it, until I deprogrammed and took the blinders off, its like they cant express themselves without saying Jehovah, organization, truth or some other trigger word, its very annoying. I played out every scenario in my head and the outcome is just like you described. So I decided on a slow fade, I don't think there is a right or wrong solution just what work for you, in your situation.
Regardless, It seams we lose, no matter what. The cruel words that there was "no point, you are going to die at Armageddon anyways" is really the crux of of the problem. They are so brain washed, they would rather give up their 'now' with you, there future grand kids and life's memories for a illogical future fantasy a utopia contrived by men. These very men that have built an empire on duplicity, their own literature convicts them.
Take your time and say nothing to the Elders, "the only power they have is the power we give them". Strip them of that power and they shrink before your eyes. Welcome to the forum, read some of the 'waking up' experiences and post as much as you like, it therapeutic.