Miltonia with wilting flowers, squishy pseudo bulb, and black marks near base

[estación seca]

This is how they die when conditions aren't proper. I don't think the primary problem is rot. If roots are dead it is likely due to being too dry, not getting enough air or getting too hot at some point.

I don't know what happened, but Miltoniopsis are hard to revive when they start going downhill. Uprooting the plant and cutting it up is unlikely to help. I personally wouldn't let them get partly dry before watering, but I'm not a good Miltoniopsis grower.