Watering should be stopped completely at the beginning of November. Make sure that the soil is not too moist when you bring your Plumeria into the winter quarters.
Since you no longer water, you no longer need to fertilise. The slow-release fertiliser you gave in May is now also losing its effect.
Please do not cut any more cuttings now. This would only unnecessarily take strength from the mother plant, which it urgently needs for the winter break.
You should not expect fresh flowers now. Maybe (certainly) next year again. Stragglers are of course an exception. If a plant is still in heavy bloom, water it carefully now and then!
No, please do not sow seeds. Just have a look at what we have written on the subject of frangipani seeds.
Repotting now would be completely wrong, because then roots could be damaged and that just before the winter break. Not a good idea!
Do not obtain any more cuttings now. The temperatures are now no longer ideal for rooting and keeping them in the bathroom... You need a tolerant partner for this!