Terminal window too tiny

I am running on Ubuntu breezy, a debian based distro and I installed via
apt-get which reports version 0.16.5-12.  

Font support warning message:

xt5250 host
Warning: Missing charsets in String to FontSet conversion
Warning: Unable to load any usable fontset

By default, LANG on my box is 
LANG=en_US.UTF-8

According to google, I can:
LANG=C xt5250 host

And the warnings disappear, but I am unclear on if that is the correct
behavior, or what the ramifications of doing so are.  What exactly is
the actual cause of the warning message and solution?

The real issue that I'm trying to solve is that the terminal window is
very tiny and unreadable.  To partially remedy, I hit control-right
click and select 'huge', but it's still not large enough for my taste,
though it is usable.

Advice appreciated.

Thank you.

Regards,
Rich