A couple of points, Pippa. Firstly, remember that Cymbidiums like to be pot bound so do not be surprised if you get no flowers the season after repotting. Then it is the diurnal range of temperatures which initiates buds. Mine live in my cool greenhouse all year. Min 10c but max27/28 in summer with all windows and door open March to October. I found that putting outside in summer just encouraged nasties to get on the plant and in the compost.
Secondly, I notice you are in South Wales. There is an excellent society which meets at the National Botanic Garden of Wales so they will be able to give specific advice for local conditions. I know several people from that Society and they are good growers. Take a look at
The Orchid Study Group – For everyone with an interest in orchids. I can give PM you a contact if that would be helpful.