If 15 years old, this must be a hardy fuchsia :-)

I would not have cut the plant back so severely. In my climate, hardy fuchsias hold on their foliage well into the early winter and the plant is still photosynthesizing. Photosynthesis generates roots. However, it is on the verge of its dormant period so the need for those roots now is not as acute.

I'd leave it outdoors as long as possible - at least until weather got pretty cold. And should it survive this ordeal, I might think twice about the bonsai plans. Bonsais are typically started from very young and quite small plants - that way they are very malleable and can be trained into desired habits. A 15 Y.O., shrub with a 3" trunk is a bit senior for this process :-)

Hi Gardengal. Yes its a hardy Fuschia. Its a Beacon. Red and purple. Its been growing outside in the wild NZ wind and weather.
Well whats done is done. I'm just hoping and praying that come spring i will see some small buds smiling at me.
I couldn't do anything differently. My main worry is that is was very loose in the ground from the constant wind we have here in Wellington NZ. The soil fell off and absolutely no fine rooting. Only biggish roots.

Just a follow up... I'm pleased to report that the fuchsia started budding in spring and now is growing exceptionally well. Remarkably tough stuff.