I live in SW Florida and consider myself fortunate for those few days when I can process at 75 degrees F (24 C, which is what my thermometer shows) without a lot of fanfare. That said, during the months of January through March is not too difficult to ensure that all liquids are at 75 F at the start of the process and (hope) that they maintain that temperature throughout.
More troubling than ensuring consistent (and in-range temperatures) for developer, stop and fix, is ensuring acceptable temperatures throughout the rinse procedure. To ensure that the rinse is within acceptable limits I maintain fresh water in 1 gallon plastic containers in a cool place. I use Ilford's three inversion wash method--meaning that I avoid T-Grain films in the warmer months. This also means that I use a Hypo wash aid between the fixer (which is neutral) and the wash cycle. (It also means that I cycle "old" water out and replenish with fresh water every two weeks.)
In the summertime (which seems year round lately) I process in the house, in the evenings when the ambient temperature has maintained 75 degrees for several hours--meaning that all solutions are stable (which also means that I often process in the wee hours of the morning). In the so-called winter month (we no longer have winter that extends longer than a week or so), I process in my attached garage, which I am in the process of insulating. I intend to also purchase a portable bi-level unit once I've completed the insulation installations. Apart from several weeks, I still need to maintain the Ilford wash sequence because the water coming out of the garage tap is > 80 degrees F.
I am hopeful that given these tools I can extend my developing activities for more than two or four months out of the year (without a lot of stress).
The only real problems/complaints that I have is the lack of lots of developing data for film processing at temperatures > 68 degrees F on the various Internet sites. I do use some mathematics for performing temperature adjustments but for some developers this is more feasible than others.