I did it with my live system. At first everything looked fine, none of the errors I had during the day in testing environment. But then whe my system said "please reboot" it booted into grub rescue mode. This was then also kind of broken and it rescued nothing with the help of google.
I then booted my normal OS with the help of Super Grub2 Disk. After that i did the steps suggested over at supergrubdisk.org.
I'm on 4.1.20-1 (Arrakis) now. All my mainly used features are alive.
Thanks to everyone! Wont miss an EOL date again.