If you don’t plan on living there much longer then don’t stress yourself about someone else’s problem. And you’re right, it’s silly for her to see a blatant problem and try to ignore it. The cost of repairing termite damage will be far more expensive than fumigation. I would spot treat obvious places with something like this TERRO T1901-6 Carpenter Ant & Termite Killer, Orange https://www.amazon.com/dp/B07D6WVZ9W/ref=cm_sw_r_cp_api_i_SET54W7KEYKVXHK4JDQR to slow the droppings until you are out of there!
So I searched for Carpenter Ants in the Q&A section of the Amazon link you provided above and it looks like Terro's customer service recommends a different product Carpenter Ants: