I can do all-in for $100, then $200, then $400, then $800 -- I have before, and results have been mixed (like everyone else).
Once I get up to four figures, though, I stop. In other words, if I take $100 and turn it into $1600 (approximately) after four straight hits, I use that $1600 and start gambling wisely with it. I'm with you re: off-shore balances; even though I'm a bubble-gum gambler unit-wise compared to a lot of you, I still don't like keeping more than $2-4 grand in a given account at a time without cashing some of it out. I don't want to get Bet Islands-ed.
Plus, to a lot of people, their deposit is their bankroll.