If you just wanted to slink along at a slow pace, the one position in 4 low is kinda like a creeper gear on a tractor. You could get out and walk beside it without it shifting into second and making you trot.
Make sure in the settings the auto fan control is not set to low. In my 2018 the auto button just goes to the fan speed set in settings. I liked the way my 03 Yukon worked, would blow on high till temp reached then slow down to maintain temp. A step backwards from 2003. I have a 2018 Denali so the programming may be different.