You are using an out of date browser. It may not display this or other websites correctly. You should upgrade or use an alternative browser.
alternatehistory.com
How many more SSRs could plausibly have comprised the USSR? POD as early as 1900 if few effects before 1914. Borders not much past the OTL USSR's.
I could see the north caucasus becoming one. Karelia maybe, especially with a more successful winter war. Maybe a far eastern SSR instead of merging the republic back into the Russian SSR. the baltic states could have been broken up different;y. Latvia especially could easily be broken into 2 or 3. Kaliningrad oblast might be an SSR instead. Tuva easily.
What else?
What would be the effects if the USSR broke up similarly to OTL?