And just to add my own 2 cents, if houses are 1930s or earlier, and still in decent livable shape, tearing them down to build something new and generic ruins the character and history of the area, and in my opinion leaves it worse off in the end.
There is one other possibility. If the 2 homes are horrible, but have good well and septic you could call the fire dept. Have them practice and get rid of your houses that way. Then drag in a trailer or double wide. You now have 2 sellable properties. It is a bit of an expense and a gamble, but could be a workable plan.