Removing Cigarette Smoke Odor From Wood Paneling

[Nicholas TenBrink]

Hi everyone,

I'm looking at purchasing a property that has been inhabited by two heavy indoor smokers, they've been smoking indoors for 25+yrs in the property and it reeks heavily of cigarette smoke(even as a former smoker it's too much). 

The interior wall surfaces are all tongue and groove boards (cedar), there are visible nicotine stains on the air returns.
Every single surface will need to be cleaned in some capacity, but I am left scratching my head at effective solutions.
I've found a few anecdotal recommendations about using white vinegar or TrisodiumPhosphate, but when you need to scrub the walls and the ceilings of a 1700+ sqft house that seems pretty daunting and time consuming given that it is tongue and groove. I also thought about the idea of hiring a company like ServPro/etc that specializes in post fire/smoke damage remediation.

My worse case scenario is gut the house, and repanel , but I would rather not need to do that.
At this time I am seriously considering making an offer with a significantly reduced price due to the long term smoke damage.

What are your thoughts? Concerns? Advice?
Thanks for reading!