We too are in the same position. This house was built in the 1940's and we are planning a total remodeling of it from the siding to the wiring and everything in-between. We are meeting with an architect to advise what we want to do and get his expert opinion, although getting the final blueprint from him will be expensive(approx $4000.) We will be adding rooms and expanding existing ones, adding a bath, etc. It took us over a year to actually make the decision to go ahead with this project, but we bit the bullet and said "go for it".
Anybody with any good advice please respond! Thank you all