For a start, the Ilford Time & Temperature chart is a reasonable starting point for varying development time for differences in temperature.
For donkey's years I have standardised on 24º C summer and winter because the Sydney water supply is as near as damn it to 24º in summer and so I can keep one set of times all year 'round.
I had tested a great many Film/Developer combinations using the BTZS method including TMX and Rodinal. But it dawns on me now that the BTZS software was PC only and so I had my files on a PC up at Vanbar. Their computer died and they trashed it, along with all my test results.
Looking up Anchell & Troop, their recommendation for T-Max100 in Rodinal 1+50 at 100 ISO is @ 20ºC is 12 minutes which I consider to be a couple of minutes too long. I have used T-Max100 in Rodinal 1+100 and that was only 11 minutes.
"Photography was not a bastard left by science on the doorstep of art, but a legitimate child of the Western pictorial tradition." —Robert Galassi