Do a "dry run" with water. Measure temperature of water before and after development. Adjust as necessary. Make sure the process is repeatable. Keep notes, especially related to ambient temperature.
You could try applying heat to the spinning drum with a hair dryer or some such to help maintain temperature.
Yes - this special method I wanted to advice too - but I possible couldn't explain it better. So we have to know with this method it isn't correct in concern of c-41 specifications because you are outside of reguar temperatures.
C-41 chemistry need exact 37,8 degree celsius during full time of the process :
(3'min.15"sec.).
The tollerance of spread given is very very hard (+- 0,3 dergree celsius as I remember correct - may be it is indeed 0,2 degree).
Therefore some recomanded temperature control via machines.
But if you are allone (without a machine) you may use a temperature as aritmetric mean.
Pls. don't allowe the chems to come more out of this temperature.
It is just a hart issue today because this standard from temperature with c41 is designed to the advantage of labs. (workflow on high level in regard of shorter development).
I know a lot of old process standards with lower temperatures.This would be much easier to handle todays without temperature control.
Notice : If you have a big volume of developer (for example 160liters) the lost of temperature is a very little within some
minutes (may be within a limit of 0,05 degree) so it isn't a real hart work just with old fashioned lab machines to regulate temperature.
The same is with drum developement (low volume) and less temperature differences (for example room temperature 24 degree celsius - and the use of old fashioned processes - as in the past - with 26 degree developer temperature).
But in the northern hemisphere you will have no chance with a process due to a need of 37,8 degree.
So - OP : try this (to me best) method if you can't get any kind of automatic temperature control.
May be - I just can't know now - but may be this method would also be nearly OK to PE. And then it is realy OK

!!!
As I remember PE refered to the concern of couplers and the design in regard to the need of these exact temperatures of modern c41 or in opposite direction.So it goes not only to the issues of time of developement.If this would go so easy you may adjust the time of development just with a corection factor (like in bw) in concern of developer temperature.
Some advices of Rollei Chems (Fujihunt derivates) went in this direction (converting time tables) with 30 /degree celsius, 25 degree celsius.
But also some warned to get color shifts with c41 films and instabile colors as a possible result of wrong temperatures.
(long time instability issues - after years not after month or weeks

...)
with regards