So far, it's going fine. I really was prepped, so I could jump in less than 6 hours on the day before the event started, including building construction time. (That is, during most of that I could go do other things.) It helps, of course, that I was only jumping to Early Medieval; for many later ages, I assume, building construction takes a lot longer! And I negotiate rather than fight, so it was good enough to get early tech that permits the goods plants I have a boost for, plus of course Multi-Story Houses & Economics. And while I couldn't get to the tech expansions on this plan, the diamond expansions & tearing down some of my earlier goods factories have given me plenty of room for EMA plants. I have to admit, I haven't put in the base Bridge yet, so as to have real estate for Event Quest buildings.
Fighters, I can see, would have to gobble a lot more real estate on the tech tree to feel comfortable! However, as a negotiator, I could prep by buying high-Age goods and trading them down in preparation for my jump. I currently still have a stash of Late Medieval goods that I've been turning into EMA & IA goods as I've needed them while the event progresses. So yes, I cheated! LOL, it may take that to feel comfortable jumping the day before the event -- but then, I told you all I was prepared!