Terminal size shrinks whenever using nano over serial connection
I'm running a serial connection to one of those neat ARM boards running linux. Basically I'm connecting via USB serial connection that pops up on my main linux machine as /dev/ttyUSB0. I use a program called "screen" to connect via this tty and login onto the remote board. The command is "screen /dev/ttyUSB0 115200" and I can successfully connect like this.
Now I'm being bugged by something. On my PC I use XFCE desktop and a terminal emulator, which I can resize at will with my mouse. The text from the serial session will normally strech across the whole terminal. However whenever I try to edit a file with a program like nano or vim, the terminal suddenly shrinks to a very small portion of the original size. Don't get me wrong, the terminal window stays the same size, but the content is suddenly limited to a very small portion on the top-left of the window. If I recall correctly, the dimensions are 24x80 characters.
Is there a way to use a larger terminal size?
I.e. how do I make it so that nano streches across the entire terminal window?
Thanks in advance!