I-130- My Wife is about to get her Immigration Visa. How long will she have to enter the US with this visa?

She'll have 6 months in which to travel to the US.

However, we were told at our interview that if there was a reason we weren't going to be able to travel within that 6 months (ie, house not selling etc), to let them know and they would hold off on stamping our passports.

She can leave the US almost immediately, though it does take approximately 3 months for her to get her actual greencard. Bear in mind that repeated long absenses will put her residency at risk.

She has to use the visa withing 6 months of it being issued to her.

If she's in such a big hurry to leave why not forget the whole idea of immigrating to the United States? A green card is for permanent residents. You'll note the word "permanent." If she fools around, or plays games with coming and going, she'll have her green card revoked.

you can file an I-131 request for travel document. I takes about 4 months from my area but you can use the link below to check out times in your area. This will give your wife an "advanced parole" to leave and return to the US. You might also want to talk to a USCIS official. They have been known to speed things up if the situation should be sped up(no guarantees). Bring along you I-131 ASAP and see what happens.

She has 6 months before the visa becomes invalid. She can leave the county as soon as she enters but why take that chance.

She can get a Advanced Travel Documant that will allow her to leave usually within 30-45 days of filing. The form used to apply for the travel document is a I-131. I am a visa processor with http://www.ezvisa.us/