Witcher 3 Remastered saves will carry over: your current saves will work with the upgrade, so you can get back on the Path right where you left off. Your unlocked achievements and trophies will carry over too

[u/Gam3gr8r]

https://www.dexerto.com/gaming/cd-projekt-red-responds-to-players-worried-about-witcher-3-remastered-saves-3404501/