A vee beam or rhombic set up would give you impressive gain, albeit
with a narrow beamwidth... All the factors would have to be right...
I won't take the time to do the search for you, but 'try vhf rhombic'
for starting a search... Older ARRL VHF antenna books address this
issue...

If you can run a wire out the window, you can run a rope.. Think about
a homebrew, long boom Quagi/Yagi, but with the elements vertical...
Again, what directions are available to you... Also a broadside array
could be suspended from a rope for directions opposite the direction of
the rope...

denny / k8do