In European countries, the COVID-19 pandemic has given rise to a demanding work situation for office employees who have been required to work from home (hereinafter referred to as remote workers). Due to curfews, school closures, and leisure restrictions in Austria, remote work circumstances have changed compared to before the pandemic. By combining event system theory with transactional stress theory, we aim to identify the most important resources for maintaining remote workers’ well-being, perceived productivity, and engagement during the COVID-19 pandemic. We collected daily data (five working days for each remote worker) once from March to May 2020 (2222 employees) and again from November 2020 to January 2021 (1268 employees) and explored the role of personal (self-goal setting, self-efficacy, home-office experience), external (equipment at home), and organizational (work-related and social) resources for changes in well-being, perceived productivity, and engagement. Well-being and engagement decreased less when remote workers indicated high resources of self-efficacy and social support at the beginning of the crises. Results further reveal that an improvement in resources from the first to the second measurement was associated with a reduced decline in well-being, productivity, and engagement, respectively. We discuss implications for HRM and provide suggestions for future research.