My lifetime estate in the house from spouse requires maintaining a reasonable state of repair and further stated do reasonable maintenance and upkeep. How large a cost would exceed this requirement and be something the eventual owners will have to pay

Where? Reasonable is in the eyes of the beholder.

I don't know that there is a dollar amount. In NY a rule of thumb is what percentage of the total value is the repair. For example, the house is valued at $50,000. $25,000 in "reasonable repair" is NOT reasonable.

What is your specific question - what type of repair? Remodeling?

this is NC. The county values the house & detached garage at about $180,000.00. Some wiring in garage needs corrected. Termite people say I should put vapor barrier in crawl space ($500). Dishwasher not work now. These sort of things.

Reasonable repair would be what would keep it from falling apart by the time you die and the property vests in the remaindermen. The idea is to do what is necessary so that property doesn't depreciate.

Those are things that should not be let go to all have a one time, when dishwasher goes out, you fix or replace. You have annual termite spray so damage is not done. Has there ever been a vapor barrier in crawl space? Do most homes this age and condiion have them.
But the things you have listed are minor and would be expected in my opinion