How long can you go without social interaction?
My longest was basically the whole year on my own and I did not have a problem with that in that moment. (no family, no friends, no job, only student in the class but even that was only 4 months in a year, always driving in empty public buses ... etc.)
How long can you go without alone time?
A few days if I really like the people. If not even the 15 minutes can be too much.
I have a ability to be with people but not be mentaly there with them ... and this factor can greatly prolonge social time for me as an introverted person.
What situations drain you the most--clubs, seminars, a weekend alone, parties, etc?
Unwanted situations do not really drain me, they annoy me. (and that can be draining)
But this depends on the specifics: do I like the people there, do I like the music at the party, is this seminar something that interest me or the lecturer just sucks ... etc.
What energizes you?
Moving towards my goals, twisted humor, making plans for the whole group, science/technology talk, field trips/adventures, board games ...
How long does it take to recover from a draining situation?
However I can often just say to myself "this sucks" in unwaned/boring situations in which there is a lot of people I don't really know. Therefore I usually just go away without goodbye and I get instant recharge of energy as I go throughout door(s).