A good habit is to always make a copy of your surface and put it on a backup layer before you insert any isoparms. Once you do, that’s pretty much the end of the road since you can not undo insertion. You can not reposition (or reparameterize may be a better word) the isoparm. If you think of your surface as a math equation, when you insert that isoparm it’s tied to a specific parameter on the surface so while you can move the CV’s around and the isoparms will move, their parameter (or relative position) will still be the same. At that point you either have to rebuild your surface (which may not yield the original result you started with) or recreate it from scratch.
If you want your isoparms to be nice and evenly spaced, consider upping the spans manually on the box in the control panel, or hold the “alt” key to automatically put the isoparm at the halfway point. (Ctrl+Alt will snap to an isoparm on an adjacent surface)