The logistics of the rule have not yet been announced. The current plan indicates that our spouse will not need to leave the US until the scheduled date of her interview at the consulate and she will only need to be gone a few days.
The new provisional waiver allows you to get a "yes" or "no" answer whether the waiver will be granted BEFORE your wife leaves the country. If her waiver is approved, she will leave the U.S. to interview. It is anticipated that as long as there are no other issues with her visa application that immigrants will spend weeks outside the U.S. rather than months or years.
BUT these waivers are extremely difficult to get unless you can prove extreme hardship to a U.S. citizen relative. Don't go it alone. I highly recommend using a qualified immigration attorney who can help you prepare a convincing application.
www.gassonlaw.com - Disclaimer: This a general answer to your legal question. Unless you have a signed engagement letter with me, you should not consider this information to be legal advice.
However long it takes to get the medical exam, be interviewed, and be issued the visa.
J Charles Ferrari Eng & Nishimura 213.622.2255 The statement above is general in nature and does not constitute legal advice, as not all the facts are known. You should retain an attorney to review all the facts specific to your case in order to receive advise specific to your case. The statement above does not create an attorney/client relationship. Answers on Avvo can only be general ones, as specific answers would require knowledge of all the facts. As such, they may or may not apply to the question.