It should be around 25 ms in normal conditions. That's what I got when pinging Hetzner in Germany, from Finland, when the cable was still in use and when using a connection that routes through the cable.
I think it is slightly higher than normal. I remember getting 30-40ms pings to germany in recent years. 45-55ms is around the range it used to be in early 2010's before the direct cable from finland to germany was built.
I am don't use Hetzner, but I use ssh between Finland and Germany every day. As a matter of fact even back and forth because of tunneling. After reading the news this morning (Hetzner incident is date 3:30 UTC) I was surpised that I had not noted any lag. It remained very reponsive all day.
I have a persistent VPN tunnel between Finland and Germany and I’ve not noticed really any disruptions. If it had cut out for even a moment, it would’ve interrupted my services (since they don’t recover gracefully at the moment) and I would’ve found out.
If you want to know if they are affected, search for "Looking glass hetzner". It will help you better than ICMP PING.
See https://bgp.he.net/AS24940 for example.