Since you mention the TV, it seems there's a big factor missing in both the article and the discussion here. Namely, that sauna time is for many people the only time they ever take to be in silence, without the countless distractions otherwise bombarding our nervous systems. I.e. it's basically a form of informal meditation, which is known to have a lot of benefic impacts on body and mind. So maybe skip the TV part?...

I recently got an outdoor sauna at home, and that's definitely a key benefit ...sitting in silence without any devices, no smart phones, watches or music for at least 15-20 minutes.