Solved Scale down VNC output to fit my screen

Time to time I'm using TightVNC to connect to remote Windows machines (helping users), and it is very annoying thing when remote screen is 2x larger than my so I need much scrolling. So I thinking what is the simpliest solution to scale down output of TightVNC to fit my screen?
-is there any VNC client I don't know that has such built-in functionality? Or similar free software?
-is there any kind of "proxy layer" that possible to insert between app and window manager?
-is there any lightweight composing window manager that can tell big window size to app, then scale down output?
-other ideas?