For me, at least, it depends on how much comic you've already created. If you're just starting out, then I'm not too hooked on your story yet and I don't have that much faith in your ability to follow through, so if you go awol for, say, 6 months, I'll assume you abandoned it and unsub accordingly. But if you're already a good ways in (say, with at least one finished arc), the either I'm too hooked on your comic to drop it no matter how long you hiatus or I haven't even caught up to your most recent update yet and therefore hiatus makes no difference to me 