Absolutely. We are in a legal battle with a couple of my wife's siblings. They were and are trying to take control of my wife's mother's assets. We have the upper hand, because my 89-year-old m-i-l specified my wife as trustee and health surrogate in a trust and several other documents going back 20 years. We've been taking care of her the last few years, the last year in our home. They were trying to deem her incapacitated and attempted to sieze her assets. She has mild dementia, but knows what is going on and is otherwise healthy and can still make decisions. My wife's siblings are near broke and greedy and don't care about my m-i-l. So far, our lawyer is winning the fight.
Create a power-of-attorney that takes effect only if you are incapacitated. Make sure it's someone you trust to do the right thing. Create a revocable trust, and periodically make sure it's up to date. The health surrogate directive is important. Because the wrong person caring for you will steal not only your money but your life as well, by deeming you incapable. We've seen that happen to others.
Believe it or not, the “springing” power of attorney you describe was removed as an option in Florida a couple of years ago, which is unfortunate. But good on you for getting the family to stick with the plan. That is over half the battle.