Antonin Careme, the famous French Chef, was invited in 1819 by Prince Sergei Volkonsky ( The Head of the Imperial Household) to cook for Alexander l. Prince Volkonsky was, like most Russian aristocrats at the time, a Francophile, hence the invitation.
Careme does not mention that the kitchens were anywhere else than in the Winter Palace, and that everything in the kitchens was constantly "audited", which he found an insult to his honour.
He was also invited by the Dowager Empress to Pavlovsk, where he prepared a dinner for her birthday, and also to the Catherine Palace. Here he saw for the first time a special stove designed to keep the plates warm, and where a "suite" of rooms dedicated to the preparation and service of food existed, the actual kitchen was very narrow. The kitchens at the Catherine Palace were extensively renovated after the Nazi bombardment.
Careme's visit to Russia was fairly short, but had a significant influence on Russian Cuisine, and vice versa.
On his return to France he introduced to Europe the Russian way of serving food, " Service a la Russe" which changed the way we eat to this day.
He also introduced to the west, the Russian tradition of placing flowers on dining room tables, instead of elaborate silver and porcelain dishes containing fruit etc. Probably hothouse flowers from Tsarskoe Selo, one would imagine.
I find it hard to imagine hundreds of waiters rushing through sub zero temperatures in the snow with warming dishes serving dinner to thousands of guests in the Winter Palace. There have to be very large kitchens in the basement of the building, to cater for everyone, including the hundreds of servants. Probably storage space today. I think the concept of separate kitchens, to keep smells and fire at bay, probably only applied to country houses, and places like Tsarskoe Selo where they had the space to do so. The Elagin Palace has a very beautiful kitchen building.
A bit off topic, but I thought quite interesting.