I try to keep a minimum temperature of 50°F, Tony about the same. Grow at a temperature you can afford, and possibly choose varieties that will tolerate colder conditions. Our source of heating comes from "Parwin Heaters" also with this you get good air circulation.   In my small greenhouse the minimum temperature is 40°F, on cold nights dropping lower.  This greenhouse is where I over-winter Fuchsias, Geraniums, etc.  Some plants of my Begonias were put in there to take a chance. They survive but look a little sick at the moment, but I know they will come back.  Never throw plants away too soon, they may look dead, a bit shrivelled with no leaves but they may just be in a coma (more on this later).

   My plants are kept on the dry side all winter, even in early March when new growth is beginning to appear I still only water sparingly.   I never try to push any plant into growth with feed and extra heat during low light, short day months as this leads to weak, lanky, floppy growth.

 My propagation is mainly by leaves with their stems rooted in water. I now add Perlite, Vermiculite or Grit to the water.  By using just water I found when they were ready for potting the roots just tangled around themselves in a tight bunch.  By adding the above materials they come out in a nice spread position ready for potting into small pots.  After potting they go back onto the potting bench for a couple of weeks to get established.  Small lengths of Rhizomes can be used as can stem cuttings for Canes, etc. These are inserted into compost with added Perlite.