How long do TPMS sensors last?

[NYC-SE]

So I'm coming up on the time when I'm going to have to get new tires. (Hoping to make it thru the winter on my current, original, set but we'll see.) Anyway car is 6 years old and I was wondering if it wouldn't make more sense to replace the TPMS sensors while I had the tires off. Only problem is I am a cheap bastard and I hate the idea of spending money replacing something that is still working. Of course I know that at some point the batteries will die and I will have to do it then, potentially costing more as the tires will have to be removed in order to replace the sensors at that time.

Searching online I see a lot of 5 to 8 year lifespan quotes mostly coming from tire shops, TPMS manufactures, etc., i.e. people with a vested interest in selling me the sensors, but I see very little real life experience from actual consumers. Would be interested in some real life Yaris or Toyota examples, how long did your TPMS sensors last?