What would 你 do if one piece ended.....

It's the same as 火影忍者 it will, if 火影忍者 ends everything will.

theres still 10+ years left till that happens

Then 你 deal. Just like 粉丝 of 火影忍者 或者 Bleach 或者 whatever else. In my opinion . . . 你 vocally protest as 你 watch it 你 the 苦 end if that's what happens.

Havent watched it

I'd go on living my life as normal.

i will be SAD............!!!!!!!!!