This is common misinterpretation of what Elon said. For example, during an appearance on Joe Rogan's Podcast, Elon said that with conventional rocket technology, it is possible to colonize the entire galaxy within a million years.
This DOES NOT include intergalatic space travel. The nearest large galaxy, Andromedia, is over 2.5M light years away and is unreachable by chemical rockets.
But this too is a false narrative. Our home galaxy, the Milky Way, is hurtling through space even now and will merge to form a new spherical galaxy "Milkdromeda" in about 4.5B years (same age as our solar system).
So, the TAM for Teslabot is
Pan-Galactic. all Elon has to do is wait, and stay healthy...
Cheers!
P.S. Eventually, all galaxies in our local group will either merge or have close passes, allowing humanity to colonize all reachable space. Outside the local group, where distant galaxies are not gravitationally bound to our own, eventually those places will fade from view with the Hubble flow (~75km/sec/Megaparsec). Elon will have to content himself with the ~120 Galaxies of the local group.
P.P.S. Physics is the Law; Everything else is a Suggestion.
FTL travel changes the law....