I'm also in the market for a sandbox game to get comfy with this winter, OP.
A few suggestions from me in the meantime:
>ARK (less building, more survival-focused)
>Banished (comfy town builder)
>Black & White (older sandbox god game)
>Kerbal Space Program (chibi NASA simulator)
>Paradox grand strategy games
Some of these are not strictly Minecraft-like, but they share the open-ended sandbox nature that in my experience autists fans of the genre appreciate.