Once vehicle to home standardizes (probably not until a competent federal government forces it, at least in the US), then TOU billing becomes a non-issue.

Just reserve 10-20% of your vehicle range to load smoothing, and the entire house can go to negative use during TOU premium windows. (Ideally, with the hypothetical competent gov't the TOU surcharges would be forced to be symmetric, so going slightly negative during peak hours would end up creating a large negative power bill until the surplus charges became obsolete and trended to zero).