
The tree, effectively never. Once the root plate has torn free or the stem has broken, there is no reattachment and no cabling fix. The whole question shifts to getting it off the structure without adding damage — which is a rigging problem, not a felling problem.
Now. Do not sleep or sit under the affected side tonight. Waiting does not let the tree settle into something safer: rain drives water through the opening, insulation and drywall gain weight as they wick it, and a roof section that is partially supported by the tree can drop hours after the storm passed with nobody touching anything.