I'm actually surprised you were fine with single-hose. I've never seen a single-hose portable A/C unit that did an adequate job. AIUC, the laws of physics make that rather difficult. In fact I've sometimes seen them actively make things worse. Whereas I
have seen dual-hose do an adequate job.
Also note, "survive" is a rather low bar. We're talking about encouraging some of the world's top researchers to move from the US across the ocean. I'm admittedly not in their shoes, but I imagine mere survival isn't their criterion.