The transfer of higher education to a distance format as a new trend has increased the relevance of research on the problems of assessing the quality of higher education services and its sustainable development in the post-pandemic period. The article proposes a methodological approach that includes the authors' modified Higher Education PERFormance (HEdPERF) model and importance-performance analysis. Testing of the methodology for the Russian university showed its advantages that is a comprehensive assessment of the higher education service quality. The transition to a mixed model of higher education caused the need to improve the methodology. The authors proposed to include in the questionnaire the characteristics of the quality of distance learning: correspondence of goals and content of online technology, the level of online interaction of students, conformity assessment procedures and the stated competence, clarity of assessment criteria students the opportunity to track the progress in the development of the online course, quality learning materials, quality of technical support the online technology, ease of use etc. © The Authors, published by EDP Sciences, 2020.