Everything depends on whether the space in which one is sleeping is heated or not, whether there is a window open, what the weather is like (temperature and wind), and lastly what the individual's preferences are. The colder the environment and the warmer the person wants to be, the better insulating bedclothes will be required.
Ever since the supposed "Tog" unit of measurement was put together and publicised, I have been trying to obtain a definition for it which describes, in normal units of measurements, the physics that the Tog is supposed to measure. I have established the apparently reliable fact that more togs almost certainly means more insulation and that it is meant to replace standard SI insulation measurements by being a fraction of the standard unit. Beyond that everything is very woolly (no pun intended) and the impression I have is that different manufacturers have a different concept of, say, any given Tog number - there appears to be scope for making it mean whatever suits you. This may be why, to the best of my knowledge, nobody outside the UK uses the Tog and only those who have got to know it in the UK have ever heard of it.