There are more than two survival islands located to the south of the spawn, but the two mentioned have villages with blacksmiths.
Village #1: 216 824
Village #2: 536 696
Village/temple: 264 728
Mushroom island: 835 800
There are probably a few more villages around than shown in the video, but the one shown stands right next to a desert temple.
I found this neat spot in one of the random seeds that has a village, a woodland mansion, a desert temple, and a mesa all in one place!
There is also a weird little cross hovering right above the village.
Mansion: 1330 280
Village #1: 104 -936
Village #2: -792 -856