I've done it a few times before (usually at festivals), so I understand the desire to do it especially if it's a particularly special event. You can do it and be fine, of course, as long as you take care of yourself afterwards. Many friends have gone on huge 2 or 3 day binges at festivals--in fact, my SO just did 12 pills over the span of 2 days about a week ago. Not a smart decision obviously (and not something I would ever do or recommend doing) but he's doing fine and pretty much back to his normal self. I do feel that the point of MDxx is somewhat lost in these multi-day experiences, since your serotonin receptors get pretty burned out after just one use (which is why people spread them out so much). Buttt even though I'm aware of this, it doesn't stop me or most people I know from doing it multiple times in a month (or days in a row), despite the fact that the effects are lessened. Trying to get better at it.
My main point: You'll survive two days in a row just fine--but the second day won't be nearly as magical or euphoric.