NASA is studying a possible starshade flying in formation with the Nancy Grace Roman Space Telescope (Roman). The starshade would perform weeks-long translational retargeting maneuvers between target stars. A retargeting architecture that is based on chemical propulsion and does not require ground tracking or interactions with the telescope during the retargeting cruise is introduced. Feasibility is demonstrated through a covariance analysis of the starshade-telescope relative position over several weeks using realistic sensor and actuator assumptions. Performance is sufficient for Roman to reacquire the starshade after retargeting, and the architecture is shown to be applicable to other mission concepts such as the Habitable Exoplanet Observatory (HabEx). Results are verified through high-fidelity simulations, and driving sources of uncertainty are identified to confirm the robustness of the approach.