Q.Cutting back large angel wing begonia to bring inside
I have a large angel wing begonia on my porch. It is in a 5 gallon pot and is so large that I don’t have room to bring it inside for the winter. When and how much can I prune it back?

You will need to bring your Angel Wing indoors to winter over, it will not survive outdoors in temperatures below about 45 degrees.
Angel Wings do not go dormant and will need lots of light to winter over. If the plant is leggy you can trim it back to a manageable and natural shape.
Keep the soil lightly moist and give the plant a light fertilizer feeding every 4 to 6 weeks.
I would ask for help to move the plant indoors.
Here are some links for you.
https://www.gardeningknowhow.com/ornamental/flowers/begonia/angel-wing-begonia-care.htm
https://www.gardeningknowhow.com/ornamental/flowers/begonia/annual-begonia-care.htm