Well Just by looking at a simple angle measure we Can have a rough guess on the POV cockpit that the view cone is around 130 degrees. Subtracting around 50 degrees (25 from each side and looking at the Falcons shape and dimensions.)

This feels about right to me as a rough quick look.

Also to address what you have said Fanfiltration. Yes Han would not see anything sitting down. But if you look at the position of the camera in the POV cockpit shot it is actually about Head height looking down over the dashboard. The bottom of the image does not encompass the dashboard details.

There is only the POV Cockpit shot in the original post I think that could remotely have a chance of glimpsing a part of the ship out the window (never tell me the odds)

The only other thing I thought of as perhaps a way of calculating the Extended view out the window was to draw a box around the details we see and then extend lines which are approximate as to where they would go. I would like to say though that I am not really sure about this type of calculation and if it would yield an accuracy at all. But I do feel that it shows perhaps part of a process in to figuring this out.

@Bingo one thing at a time...