How to set Cmder to not wrap text output

Try running command mode, then you will see parameters below.

Status for device CON:

Lines:          xxxx
Columns:        xxxx
Keyboard rate:  xx
Keyboard delay: x
Code page:      xxx

Remember the value of Columns, just in case you want to roll it back. Now execute command mode 1000 and the Column parameter should change to 1000. (or use any higher number till you get desired result)

This also works on cmd and powershell.

As of now, I don't believe there is a way to disable text wrapping.

Someone did open an issue related to disabling line wrapping. However, as featured in ConEmu's Roadmap:

Current ConEmu version allows neither horizontal scrolling nor setting horizontal buffer size.