@Gato_Felix, I think that you should not be trying to work out your planning by reference to what others are doing or can do. In particular, people doing 1000 TSS / week are in a different league to most of us. In particular, being older [and I’m older than you], you need to work out what your limits are in terms of intensity, duration and recovery. These are all individual to you.
Now, that said, if you are trying to construct a polarised plan, then I would suggest doing as @Gerald_M says. First, set your zones as he recommends. Then identify your Z3 sessions [threshold, VO2max or sprint] with a frequency of no more than 20% of sessions or 10% of TiZ. If you do 5 workouts / week, then that’s 1 Z3 session / week [or equivalent TiZ]; if 6 workouts / week, it’s 6 Z3 sessions every 5 weeks. And so on. You simply cannot do two VO2max sessions and some Z6/Z7 sessions every week – you’ll have no recovery.
Furthermore, if you set yourself 5 workouts / week,with 20% in Z3, ie 1 Z3/week, then that is the limit, no matter how much TSS you do. In other words: if 1000 TSS / week, then 1 Z3 / week; if 100 TSS / week, then 1 Z3 / week. Polarised is heavy on Z1! [Things are slightly different with the 10% of TiZ as the polarised prescription, of course, but even with 1000 TSS / week, that’s only 100 TSS in Z3, which is less than one hour.]
All of this depends on you and your responses to training, @Gato_Felix. And your time available, etc.