You can level Geralt as long as you have the strength.
A user on Twitter asked Marcin Momot, Community Coordinator of CD Project Red, what was the maximum level it could reach Geralt in The Witcher 3: Wild Hunt and the answer was simply: "There is no Level Cap"
So don't be afraid to waste skill points because you can earn them as long as you have the strength and desire to play the title.
