The models will work just fine. We are talking about large numbers here, and your small sample of anecdotes does not mean anything. No, there is no mass exodus. No, it is not going to change the results. Yes, the current polls are more accurate than just about any in history and we have an abundance of high-quality state level polls to back up the predictions.

If you want to know where the models are going to break down it is more likely that the state-level polling has over-corrected for the factors that caused them to miss the swing to Trump in 2016 and Biden's numbers are even better than what polls are saying (a prediction based on looking at polling at the congressional district level and then seeing how that differs from state-level polling -- the numbers are the district level are closer to national numbers than the lower statewide numbers for swing states.)