The Danube and Rhine river froze over in times my parents can remember. A strong contributing factor to why rivers today don’t freeze any more is that we’re using them to cool power plants and similar.
They froze frequently, and this was not something noted in the 18th century, before power plants. You had reindeer in the Black Forest in Caesar's time. Europe was quite a bit colder in historical times.
The current temperature is clearly significantly hotter, and the rate of change is greater,
There has not been a "warming trend for millennia." The temperature rose steadily for about 1000 years since the Roman times, up through the Medieval Warm Period, then cooled steadily until about 1800, and then have shot up recently.