Could Japan advance far into Siberia?

How far could Japan advance into Siberia before outrunning its supply system?

Probably not far into Siberia at all, given Japan's poor earlier experience against Soviet ground forces.

Japan would probably not penetrate Siberia in a meaningful way. Earlier clashes had gone badly enough that Soviet resistance, rather than the length of Japanese supply lines alone, would constrain the advance early. The continuing threat nevertheless helped keep strong Soviet formations in the eastern territories as a guard against renewed war.