The LZ collaboration is going to run their machine until at least 2030. They have almost no hope of making a meaningfully larger detector, no will you hear them suggest one. Their detector is already designed at such a scale that it contains a substantial fraction of all the needed xenon isotope available on Earth.
[1] https://news.wisc.edu/dark-matter-detection-receives-10-ton-...
Hopefully, other aparatus elsewhere are big enough too in order to spot similar events.
What I was addressing was whether this detector is big enough for a reliable discovery. In that case what you really want to constrain is the rate, such-and-such events per kilogram of xenon per year (the per-kilogram-of-xenon can be traded for a per-liter rate given the density of the xenon).