ok so in one of my old worlds (i have deleted it now) i found a savanna biome and i went exploring and found packed ice . this is kinda insane because savannas are hot. ice is cold. the packed ice did not melt. i attached a screen shot, and if you look closely at the top you can see some light coloured water. the ice might be in the plains but still thats a bug sorry i cant give you the seed number . if you do happen to have the same world as i used to have i can give you some features of it:

• plains infected village.
• savanna infected village
• big hill near beach