I have exactly the same problem. I had 4.26 installed and tried to install 4.27. It did fail to install as it did actually run out of disk space. I’ve since recovered the space as. I had some large files I’d forgotten to delete so there is around 350GB of space available. My system has a single 1TB SSD and MacOS Catalina.
It is annoying not being able to get it installed. I’ve even deleted the previous version and tried various folder locations but with little effect.
