Without Chateau's insight and protractors we can only guess on the finish times in ep 7 which would translate into depart times for ep 8.
I will try to estimate times based on the changes in sunlight and shadows. There is a great change in sun direction, almost 90 degrees from the time that Don and Nick arrived and until the Goths arrive, so there is perhaps almost a six to eight hour time span in the arrivals. So my best guess is:
Don and Nick - 11:30AM
Nat and Jenn - 12:30PM
Ron and Chris - 1:00PM
TK and Rachel - 4:30PM
Kynt and Vyxzin - 5:30 - 6:00PM
So even the Goths should be able to make tdhe 0725 flight from FLO to AMS which would get them into BOM by 2350. But they might be smart and take the later flight at 0735 which would get them to MXP in time to catch the Alitalia flight to BOM which arrives at 2310.
Not matter when the teams arrive between 2310 and 2350, by the time the find the mini pedicab and get to the gas works the teams will all be bunched up for the night waiting for the "hours of operation" to kick in the next morning!
But just to throw everyone off, the teams may have to go to a ceremonial location first, and present a wedding gift of flowers to the groom before proceeding to the Roadblock.
CBS is playing dirty with us this week by throwing in extranious shots of fish, chinese temples, african art and other stu ff from other TARS and also shot of TK and Rachel running to the pit stop from ep 7. Sure doesn't help us poor detectives.
Chateau where are you when we need you