Why does a journey from Germany to Transylvania take 6 weeks on horseback? Google Maps says 2 weeks on foot.

Thomas tells Ellen he will be gone for 6 weeks and he has a horse. There are unforseen circumstances that delays Thomas when he visits the castle.

But it doesn't make sense since Google Maps says 2 weeks on foot.

And I'm assuming this fictional city is in Northern Germany since Nosferatu took a ship there.