The closest range to me is very much like the one you describe, a wide open field of 50 yds depth with few opportunities to patch or change targets.
But it still provides useful practice.
To simulate multiple targets for transition practice, I use two sets of circles on a single target - 6 inch circles above 8 inch circles.
They will last a long time before the number of holes get confusing.
Shooting at the circles in varying order works pretty good.
You can also practice mag changes, recoil control, shot calling, one hand shooting, either hand, and lots of stuff without moving.
For stage practice, a good quality, blowback, airsoft or pellet gun works, too.
Lots of folks practice with .22s, and airguns work about as well, with one great advantage - you can do it at home, without restrictions.
Lock the doors, they're coming in the windows.