This study aimed to investigate the potential protective role of baseline resources and capabilities for experiencing challenges to emotional well-being and perceived access to and quality of diabetes care during the COVID-19 pandemic in a Danish type 2 diabetes population (N = 1608). We investigated how differences in self-efficacy, well-being capability, socioeconomic status, health status, and perceptions of diabetes care measured before the COVID-19 pandemic were related to experiences of well-being and diabetes management challenges during the pandemic. The study is based on a survey conducted shortly before the pandemic (autumn 2019) and a follow-up survey during the pandemic (autumn 2020), which included questions about impacts of the pandemic. We used this longitudinal data to quantitatively investigate in regression analyses how self-reported baseline indicators of chronic care access and quality (PACIC), self-efficacy (GSE), health (EQ VAS), and well-being capability (ICE-CAP-A), and registry-based socioeconomic indicators were associated with the probability of reporting negative impacts on emotional wellbeing and diabetes management. Results showed that respondents with higher baseline general self-efficacy and higher well-being capability scores, who more often considered care well-organised and were in better health before the pandemic, were less likely to report pandemic-related negative impacts on emotional well-being. Considering diabetes care well organised before the pandemic was associated with a lower probability of adverse impacts on diabetes care. The results thus broadly confirmed that several indicators of higher levels of baseline resources and capabilities were associated with a lower probability of reporting negative impacts of the pandemic. However, some variation in predictors was observed for general well-being outcomes, compared to diabetes-care specific challenges, and findings on socioeconomic status as indicated by education were mixed.