If you're sitting on substantial gains, I would consider liquidating half, and letting the rest ride for the long term.
Simple example. You mined 1,000 a long time ago, and held on to them.
Now you're sitting on a million dollars in 'paper' gains. Take half a million out, do whatever makes sense with the gains.
If bitcoin goes to $100,000 down the road, you've still got a massive holding worth $50 million. You're not going to miss the other $50 million so much, frankly. You just won the lottery. Most likely bitcoin is either going to soar a lot higher, or crash into some disaster (for any number of reasons).