"However, I dont see any point in watching TV at a low HR for hours."
likewise. all my turbo sessions have some structure - a mix of established sessions that I can play around with (gearing, times, cadence) and Sufferfest videos cover most things. or just working to music tempo (I have a turbo playlist) can see some hard work being done.
"I really am a sweaty bastard."
me also! what time until the first drip hits the floor is an indication of how hard I'm working in a cold garage, it's usually around 8 mins on a 30 min session as 5 mins of that will be warmup and then bam into some high intensity to get the 1st drip rolling down. my missus conversely doesn't puddle the floor anything like I do although she'll be working as hard.