You can run the engine for quite sometime if you don't abuse it and minimize engine load (Not much ac, no offroading, no towing, no road racing, hard acceleration etc). A liter in 200 kms is when you should be really really worried (not kidding, just an inside joke here...)
If your asking whether to replace or overhaul, its is a long discussion, nevertheless both options have pros and cons. Depends on what your more comfortable with in the end....