Would "Location profiles" bookmark mode be better for your needs?
https://winscp.net/eng/docs/ui_locationprofile

I've got a ridiculous amount of bookmarks and the default window size is small. I see no way to alter the size using preferences or using the mouse to increase the length. It would be nice to have that option, as well as the ability to keep that window open when multi-tasking. Keep up the great work. Winscp rocks!