Where else can they go with the time they have?
I can't say where Spirit will go next, but it would seem that
Opportunity's final major exploration destination is in Victoria
Crater. The next interesting features in its region of Meridiani
are thought to be too far away even for these long-lived
robot geologists to get to.
I get the feeling that even when they finally stop moving,
their lack of mobility will not end their overall functioning.
And Mars is not a completely static world.