Estonia has a lot of Russians. One city on the border is 90% Russian. It’s only matter of time until Russia resumes defacto control there at the ballot box, IMO.
There are very few Russians in Poland, or very few that would admit to it.
You very likely will get your ass kicked in Warsaw if someone hears you speaking Russian.
ethnic Russians in Estonia also appreciate their E.U. perks and living standards and scoff at the prospect of moving back over the border - a conundrum indeed.