Rush hour isn't all that bad. On your arrival, it may take an hour or more but not too bad if you use the expressway. As for departure if your flight does leave at 0800, you'd want to leave for the airport by 0630 at the very latest and that's before rush hour starts (I've done 2 departures at 0600 or earlier, and one around 10am lately and arriving back around 3pm). No problem getting to/from the airport via the expressway.