Conversational agents (CAs) such as Google Home or Alexa offer empowering opportunities for dyads composed of older adults with mild cognitive impairment (MCI) and their care partners. CAs support coordination and planning between the two, and can amplify the support that the care partner needs to provide. In this study, we observed how ten such dyads interacted with a Google Home over 10 weeks. We logged and analyzed 3,878 total interactions, interviewed the dyads to better understand their experiences, and also surveyed their individual preferences and priorities for automated assistance in the home. We found that CAs empowered both the people who had MCI, and their care partners. We observed that the utility of the CA in the day-to-day lives of users largely depended on how much the care partner scaffolded promising functionality, setting it up and contextualizing it for specific needs and desires.