Move the Capital City

ummm, you probably never experienced Krasnoyarsk or Novosibirsk but they are far from poverty.
Moscow gets about as hot and cold as those two cities do as well.

That's now, but once either becomes capital, 100 of Ks of people will start to move in from surrounding areas, just like they did to Moscow in Soviet times, to escape shortages, poverty, & for more opportunities. FYI, Moscow climate is milder:
https://en.wikipedia.org/wiki/Climate_of_Moscow
https://en.wikipedia.org/wiki/Novosibirsk#Climate
https://en.wikipedia.org/wiki/Krasnoyarsk#Climate

Supplying them year round with produce & other foodstuffs, not to mention anything else not locally produced, from the West & Southern/Northern/Eastern seaports will be more costly.

2.) St. Petersburg, 3.) Sochi, 4.) 5.)Volgograd or Kazan.

St. Petersburg, Vladivostok & Sochi r occasional meeting places; Volgograd is a symbolic city like Sevastopol; Kazan is the capital of Tatarstan & can't be given any other larger status.
All roads led to Rome in ancient times; now they lead to Moscow, the 3rd Rome.