Do you have a sump pump in the basement that you could drain it to?
I did some googling, and
see window dehumidifiers referred to fairly frequently but struck out on finding someone who sells them.
Since they're mentioned, though, it's worth continuing to search, but an option you might consider if you can't find one is to put a
small pump in the dehumidifiers reservoir to pump it out the window. Yes, it's a bit "rube goldberg" but it would work in a pinch.