How long should it take to conquer and subdue a country the size of Texas

 So far the Russians have been at it for three days. According to the TV, the Ukrainians have put up a stout defense and slowed the Russians down.  I'm not an experienced Army guy (my service was in USAF), but I would have expected conquering a piece of real estate the size of Texas would take three weeks (or more).   I wish the Ukrainians well and I love hearing about Russians getting shot down by little old grandmothers wielding AK47s. I am not really convinced that the Russians have been repelled, yet.   Some video of Stingers taking down Russian choppers would be nice.  Some video of Javelin anti tank missiles taking out tanks, or armored personnel carriers, or just plain army trucks, would also be nice.