For me, this helped:
I checked locale on my local shell in terminal
$ locale
LANG="cs_CZ.UTF-8"
LC_COLLATE="cs_CZ.UTF-8"
Then connected to any remote host I am using via ssh and edited file /etc/profile as root – at the end I added line:
export LANG=cs_CZ.UTF-8
After next connection it works fine in bash, ls and nano.