Right now, aides and friends say, Hillary Rodham Clinton’s plan looks like this: exit the State Department shortly after Inauguration Day and then seclude herself to rest and reflect on what she wants to do for the next few years. Those who have invited her for 2013 engagements have been told not to even ask again until April or May…

She is likely to use her husband’s foundation as at least a temporary perch, several former aides said, and she has been considering a new book — not a painful examination of her failed 2008 presidential bid, as she once proposed, but a more upbeat look at her time as secretary of state.

For the moment, Mrs. Clinton may appear to be a figure of nearly limitless possibility, and her name has come up for prestigious jobs: president of Yale University, head of George Soros’s foundation. But being Hillary Clinton is never a simple matter, and her next few years are less a blank check than an equation with multiple variables. Her status is singular but complicated: half an ex-presidential partnership, a woman at the peak of her influence who will soon find herself without portfolio, and an instant presidential front-runner (a title that did not work out well last time).