Be as vague as possible, and if you can avoid face to face contact (eg. if you can just send them an email) even better.
"I'm having some issues right now that I have to take care of. Thanks so much for your loving kindness, brothers, I really appreciate it, but this is something I am working out on my own right now, privately. When I'm ready to discuss it with you, I will contact you. Thanks for understanding."
They may not like it, but there's a chance they'll respect it and leave you alone for awhile. It's just a stalling tactic, though. It is unlikely they'll give up if they keep seeing your family at the KH every week. So it's time to work on your family, as well.
How do they feel about your fade? Have you hit them with anything apostate yet? If not, good. Don't.
Take the lead in Family Worship Night and read ONLY the Bible. Focus on scriptures that contradict Watchtower doctrine or that the WT tends to avoid/ignore because it doesn't fit in line with their dogma. Read scriptures together with your family and ask them what the scripture said. Make sure they say it out loud. (For instance, you may read Revelation 7:9 and then Revelation 19:1, then ask: "Who are these verses talking about?" Once identified, ask: "Where does the verse say they are?") You will see the cognitive dissonance on their face.
You can do the same thing with Christ saying "you will be witnesses of me" in Acts, not judging people based on holiday participation in Romans 14, Jesus answering prayers in John 14, or any other non-JW types of verses that speak for themselves. It is important not to tell what they mean or what you think they mean. Let the verses themselves cause dissonance. This does two things.
One, it protects you from liability because you never came out and said "holidays are ok" or "the great crowd goes to heaven" at all. The Bible did.
Two, it lets the Bible, which JWs believe is God's direct, literal, and inerrent word, contradict the Watchtower doctrine itself. That's powerful to a person of faith.
It will perhaps take several weeks or months of this sort of Family Worship night for your family to wake up, but the dissonance should open them to questioning and examining the Bible alone fairly quickly because no matter how mentally enslaved one is, there is someone in there starving for freedom.
Good luck. We're all with you and your family.