In warm areas, this can grow into a good sized shrub of 6-8' by 3-4'. If you are growing it in a container (best plan in colder areas for ease of winter protection), you can expect it to remain somewhat smaller, maybe half that size.

Nonhardy abutilons don't like cold temperatures, so I'd bring in once it gets close to 40F overnight - don't wait for frost. And grow it as a houseplant over winter. It needs bright light and sufficient moisture - don't let it dry out. You can trim it back to reduce legginess before you take it back outside next season. Save those trimmings for cuttings - abutilons are quite easy to strike from cuttings.