imo, playing the witcher 3 once a year is the way to go, along with marathons of all the other things you love. i mean, here i am on my second playthrough with a bunch of personal rules in place, but i don't think it's possible for me to be burnt out by this masterpiece just yet. i suppose if you're playing it every single day for 18 days and you're not as insane as me, yeah, it's going to burn you out.
anyway, taking a break and pacing yourself is probably a good idea. it's a proper contribution to human culture, so i imagine you'll be able to appreciate it again in 18 days witcher-free.
(also damn that soundtrack)