I was recently testing in the 1.13 snapshot (Most recent one) and actually found an amazing set of survival islands! The seed is 6983761022495369637, I found it literally just by making a new randomly generated world! I don't know if this will still work in the 1.13 full update or not, if they do more drastic biome changes or something similar this might not work, but it is worth checking out! So far I have found six different islands plus an ocean monument which is right next to the spawn island! Enjoy!

P.S. Sorry about the poor screenshot quality... I can't run snapshots on Optifine and I cant run shaders without Optifine DX...