A ship attempting to rescue anyone an iceberg would have risked damage to itself.

Sage 2112, I had a friend who was a career navy man, and he told me 2 1/2 hours is more than enough time for those in the know to make adequate emergency flotation devices.
That said, a lot of people Did not understand the seriousness of the situation until things got very bad, and then did not have time.
Check out this very, very cool youtube video, based 100% on survivor accounts.
www.youtube.com/watch?v=CsaDyavJo1U
The first several quotes are all about how no one thought the damage was significant or life-threatening at all. That it was initially thought to be a joke.
Although a bunch of unsteerable makeshift rafts would be quite the chore to round up the next morning.
And who knows? As you speculated, there may have been survivors on rafts who drifted off and were not picked up. That fate would really bite the big one

I sometimes wonder why (or if) more men weren't scrambling to find pieces of wood to float on - like the one guy who was tying the deck chairs together. I guess in the chaos and panic and short timeframe, the poor souls just didn't have much of a chance. Such a shame.

Not to mention it might be tough getting people to volunteer to hop out of a lifeboat and on to an ice floe in mid ocean at night. Still, it may have been possible, according to Beesley

Hello Friends, This is a link to Chapter 7 in a librivox free audio version of Surviving 2nd Class Passenger Lawrence Beesley's book "THE LOSS OF THE SS TITANIC"
http://ia600508.us.archive.org/32/items/loss_titanic_1107_librivox/lossoftitanic_07_beesley.mp3
At 16 minutes, 24 seconds into this Chapter, Mr. Beesley Remarks that it would have been Quite Feasible to Land Persons from the Lifeboats on the Flatter Portions of the Ice Field, Had they known it was there. I personally find this potential method of Survival Fascinating and am surprised it is not more well known that Beesley felt this was the case. His account is, I believe, considered one of the most Accurate, so You'd think his opinion would Carry Weight. I think Simply because the Idea of Landing People on an Ice field in Mid Ocean, and then attempting to return to the ship (or site of the sinking, by this time) for more Passengers sounds so Far-Fetched that historians Just don't dwell on the fact that it may have actually been possible. Just a Theory, And of course, even with Night Vision, We all Know they Couldn't have gotten to the Ice Field and back with too much time to spare. Still Very Interesting none the less

None, probably. The iceberg was not of a regular shape and no one knows how stable it was, especially after getting rammed. Having people jump from ship to 'berg would not have been safe. Now if there had been some solid, flat pack ice nearby.
Your name is of no importance and you live in the pipe in the upstairs water closet.