HIV is not an easy thing to contract. There are two basic conditions needed for a transmission to take place.
1. Sufficient quantities of the infectious body fluids to come in contact with your mucus membrane.
AND
2. Exchange of body fluids takes place inside the body.
With an AND gate between the two, it may be interpreted that unprotected vaginal and anal sex is the only possible way of transmission of HIV in sexual route of transmission.
Nobody has ever contacted HIV the way you suspect (contact of vaginal fluid with urethra during condom unrolling) relax and move on.
If condoms are used correctly and they don’t fail then they are 100% guarantee that they will prevent HIV. As for how long can the virus live outside the host body I am not in a position to answer this question.
exactly how many minutes do the hiv virus leave outside the body?
No, it's not because the virus is too exposed to the environment. The more time it's exposed the more inefficient the virus gets. The virus dies quickly outside of the body. Just remember not to remove the condom during genital contact.