Doctor Strange has lost more theaters before thanksgiving weekend than TDW did, it will have 3008 theaters left on Wednesday (TDW still had 3286):
http://www.the-numbers.com/news/217480830-Theater-Counts-Moana-Launches-in-3-875-Locations
So it's possible for it to drop more than TDW did(-22%). I think it should be pretty close. Doctor Strange has Moana to compete with, but TDW had Frozen to compete with; Frozen opened on Thanksgiving in 2013. So the effect of Moana should be cancelled out by Frozen in this comparison.
I definitely don't expect it to fall as much as 30%. I think it will be somewhere between 20-25%. Spectre (4th weekend thanksgiving) and Skyfall (3rd weekend thanksgiving) even managed to only drop by 14% on thanksgiving weekend, but I don't think Doctor Strange will drop that little.
As for 700M WW, we'll have to see how well it can hold on next week. Fantastic Beasts is doing better overseas than domestically, so that could really hurt it's chances of reaching 700M. It should get close, it's on course for 690M right now, but if it does well in Japan and has slightly better legs it could make it to 700M. It's not looking as likely as before anymore though. It's much harder to predict overseas box office because there are so many different markets and release dates to think of.
Either way Marvel have probably already made enough to break even, and they will be very happy because Doctor Strange is already a big financial success.