I was also thinking about this around the beginning of the war. It is very logical that for the reasons you explain, their nuclear capabilities are not as great as the world thinks. After the shitshow we have seen, it’s obvious that corruption and incompetence wouldn’t allow for this level of delicate nuclear maintenance on a large scale. I heard something like the US spending on nuclear arsenal upkeep is comparable to the Russian pre-war military budget.

However, according to the START treaty (iirk), US and Russia regularly checked each other’s nuclear arsenals (I assume until the start of the war), to confirm the numbers and status. Based on those inspections, the Russians seem to be still cooking. I don’t know how deep these inspections go, maybe it’s easy to put on a show. Also, I think Putin knows that MAD is the only reason he and his country still exists, so maybe they have at least a few dozens warheads in good condition, personally managed and checked by a trusted associate of his.