Mike
Luc -who wrote DSS- says 20 darks is the minimum recommended number of darks-and he has some examples in the DSS help to show the impact of more darks
( dont know many people who actually take 20 darks_ the maximum I have taken myself is 6 x 10 minutes--we are all seduced into capturing more photons and not wasting the night taking darks
I take darks every session myself..but since you already have the discipline of recording temperature at each imaging session you could easily build up a library of darks identified by temperature..I know Gary Beal does that sort of thing