My fiance and I are planning on applying for a K-1 visa within the next few weeks. I am a US citizen and I have a US passport valid for a few more years. She, however, has a "prorroga" - an extension to her already expired Venezuelan passport. If the visa process takes around a year then it's likely that when the interview happens her extension will not be valid for 6 more months. Because of the situation in Venezuela, obtaining a new passport at this time is an extremely expensive and lengthy process. Does the US rule of adding 5 years to expired Venezuelan passports still apply for the K-1 visa process?
As far as I know, the US's 5-year extension of validity for Venezuelan passports still applies. (See for example this FAQ for Diversity Visa and this CBP answer.) The 5 years starts from the end of the extension provided by the "prórroga". In any case, Venezuela is part of the 6-month club so Venezuelan passports do not normally need to be valid for 6 months at the time of nonimmigrant entry.