The idea of the Kelvin having a metric buttload of shuttles has tickled my brain. The Kelvin was a survey ship. My guess is that it had lots of shuttles, and those shuttles had their own advanced sensors, so it could send out a whole bunch of survey teams and map an entire planet in one swath. According to that Intel site the upper nacelle seems to be just a giant hangar with a deflector on the front. That would indicate to me that the warp core is probably in the back of the saucer a la the Akira, NX, Norway or other "stardrive-less" designs. Therefore the saucer probably wouldn't make a very good lifeboat if it's full of antimatter.
So my guess would be that using the fleet of survey shuttles was the best option. Although, those shuttles seemed to be jaunting along at very low impulse, so I hope there either was another ship in the area, or they were taking a dramatic pause to bask in the starlight and waiting for the fade to jump to warp.