I will be flying in to Heathrow around 7:30 pm on a saturday at terminal one, and departing at 9:30am on sunday. I would like to get in some sight seeing. I was thinking about Taking one of the night time bus tours. Saving time is more important to me than cost though i would perfer not to pay for a taxi all the way into london either. From the research ive done i would probably take the express to paddington and then a taxi from paddington to green park where the tour starts. Then a taxi back to paddington and the express back to terminal 4 once the tour ends. Is this feasible? i want to avoid missing the express back to the airport or would it be better to just find a hotel near paddington and catch the express in the morning?