Poor and middle-class women probably ended up in the streets, or in workhouses (or any other refuge, hospice or institution their country had, I guess?), but could upper-class women, with enough assets to live the rest of their lives comfortably without a man in their house, simply stay without any male custodian?
Were there things that their status of minors didn't allow them to do (other than voting), and was the lack of a custodian a disadvantage in their daily life?
I'm assuming by your mention of workhouses that you're thinking about the 17th-19th centuries in the anglosphere, or "the west" more generally? In this context, women were not considered minors. I have a number of past answers relating to this, but I think these two are the most relevant: