Hello Stephen,
I would expect, that after a crash, you will get a popup on start, asking you, if you want to restore open files or start empty workspace... But maybe the crash is not detected because it actually hangs...
Yes, you can go in %APPDATA%\HippoEDIT\workspaces and check in file default.hewsp in Files node and delete the file making troubles. Or, if you have pasted the content in "Untitled" file, you will find that file also aside, so you can delete it. It can be also clipboard content or undo history that is loading so long. It stored in the same directory by name *.heclip and *.heundo files. You will see if they are too big.
Please share with me what was a reason for hanging. It shall not be like that even in case the file is too big. Maybe this is fixable.
BR, Alex.