Can I transplant it into my garden?

Probably not. It is likely a hybrid Florists' Azalea that will not withstand cold winter temps. It might survive the warmer months outdoors, but not the winter. There are winter hardy Azaleas but if you purchased yours is a pot and in bloom in winter, then yours is probably not one of them.

It depends upon what your minimum winter temperatures are. It looks like it never falls much below 4C in Tiverton. If that is the case, plant it out. Florist Azaleas can't handle a frost but keeping one healthy indoors is almost impossible.

Thank you for your replies, I will attempt to save it for another year indoors.

Azaleas can be successfully, but not easily grown indoors. They do best in a north or east window with cooler temps. They do not tolerate dry soil and even a single lapse in watering will cause quick leaf loss. Keep it pruned. Getting it to bloom again is very difficult unless you can provide some direct sun, cool temps, and higher humidity. Not easy.

Thank you.