having used both the vista cruise, and the all plastic Vanda cruise, on a few bikes, I'll say you are going to have to remove the grips, and carfully reposition the heaters, and re install both after positioning the vista. you will likely have to trim the outboard end of the grip also, to prevent rubbing on the bar end.
I use Gumout, and the small red tube, slid in under the grip and spritze it and begin twisting while wet to get a grip off.. no clue about your heaters, if they are glued on, more research on the adhesives will need to be addressed... for re-installing, again I spray the grip insides, and the bar, with it, and slide and slam it home, but you may want to add a stack of cardboard spacers to prevent pinching it too tight against the switch pod.
