It will the time of year after the winter thaw when the land is supposedly dry enough to armor to roll anywhere they want.
Russia also has somewhere around 300,000 soldiers in reserve, the speculation is they will take Karkiev and possibly Odessa over the summer.
The speculation is if they take both cities will they make a move on Kiev.
I’m hoping Ukraine goes into these “post-war” negotiations with Russia after it has been reduced in size to a small Kiev city block with just enough room for two small homes: one for Alexander Vindman and the other for Victoria Nuland.