What is Ella and Serge's palace used for these days?
Hmmm... It is palace traditional name "Palace Beloselsky(ih)-Belozersky(ih)".
It was bought Grand Duke Sergei Alexandrovich after marriage Ella (Grand Duchess Elizabeth (Elizaveta) Feodorovna). In 1890-1917 palace named "Sergievskiy"
In 1911(2)-1916 lived there Grand Duke Dmitriy Pavlovitch
Today it is museum and office tv-studio occupies several rooms 2 storey/floor(?)