the facts on the ground may materialize faster than European ability to adapt
Поживём - увидим, as ancient Greeks used to say.
It is my sincere hope and wish, however, that common sense on both sides will eventually prevail.
Russia is big enough already without invading yet more neighbours
It is indeed but in the current situation it is irrelevant.
If we don't get back to serious diplomacy, we will have war. And I might even be positively predisposed towards this idea if it wasn't for the fact that some of Russian nukes might still be operational. Especially that the only nukes in European NATO are in the hands of countries which are famous for either their perfidy or a certain predisposition to wave white flags. Therefore, unless Poland has a nuclear arsenal at least the size of the French one (preferably twice the size) and deployed across various strategic delivery systems, all thoughts of all-out war against Russia are retarded. If Poland has nukes, neither side will use them because Russia will realize that Poland has balls enough to retaliate, so we would be fully in the area of conventional war - a war that mathematically we already won before it even started (just like in 1941, when the USA entered the war, the Third Reich already mathematically lost - it was only a question of time). War is not a matter of heroics, medals of honour, banzai charges or patriotic march music; it is a matter of mathematics and mathematics is on our side.
So, at the end of the day, it is either nukes for Poland or sh*t the f*ck up and go back to the diplomatic table (and I prefer the latter).
Having said all that - it would break my heart if we were forced by external circumstances to go to war against our Russian neighbours and Slavic brothers. Let's all hope and pray that it will never happen.