I make little brick walls around my pots so the wind doesn't turn them over.
Similarly to caring for a bonsai, at some point one decides, "This is the biggest pot I can bring into the house for winter." But plants don't stop growing, above or below ground. So, when repotting, you can remove the old soil, trim the roots, and put plants back in the same pot. This gives them space to grow again, but doesn't require a bigger pot. Whatever mass above the soil that doesn't fit in the house, I trim it off. (If I don't want to keep the trimmings, someone usually wants to pay the postage to get them.) Many of my plants are now in the biggest pot I plan to ever give them, but I also intend to keep them around until I can't take care of them anymore.
Regarding your particular plant with the branch leaning way out to the side, when you repot, you can tilt the root ball a bit, so that part is upright. That will keep the main mass above the pot, making it take up less space.
Trees don't mind if you dig around a bit under them, as long as you let the roots dictate where you do it. Just don't try to cut through any big ones, or add so much mulch or dirt that it raises the ground level. My Mom has a huge garden under some oak trees.
