If you don't want to change the profile and roof line of the front of the house, then consider adding at the back of the house. You could add a rectangular space to the back of the house, even 2 stories high and it wouldn't detract from the front visual, as long as the exterior finishes are cohesive with what is there already.

I see you already have a dormer on one side, if you want more height in the upper level then you could build out the roof line with large dormers that could tie into the new structure as well. That would improve the current space as well as give you new space.

There are quite a few architects on Houzz who could probably give you some clever ideas for how to do it but I don't think you should feel bound by your current footprint if you want/need more space.

This is really just a 1 1/2 storey house and the advise above is good I do however not like dormers that run the length of the structure they look wrong. Bta an addition on the back would work for sure.

There’s actually already a bedroom addition built on at the rear of the house. That’s another thing that hinders my vision for the remodel.