Thanks for all your replies.
I certainly agree that one person's "blips and wobbles" are another's critical, grievous problem. As a traveller, my concern would probably be fuel shortages, but I'd assume if RS tours can't get petrol for the bus, they'd have to cancel and reimburse. Now, whether planes can refuel is another matter. Sure, we say we'd like to be stuck in our vacation world, but really we have lives we must get on with. I'm not saying this will happen, of course. Just speculating.
Also, while I hope the outcome is the same, I just can't compare this with Y2K. There is no basis for comparison. Because that turned out ok is absolutely no reason this will. And I trust an army of IT professionals like a thousand times more than I trust any government to produce results.
And while I had no intention of making any politically charged remarks, from an outsider's opinion, it seems the voters did not have all the information required to make an informed decision on the referendum in the first place.
However according to RS terms and conditions, I could change to another tour up to 60 days ahead. I've always wanted to see Belgium anyway... Haha. I'm really not trying to be a doom purveyor, but I go on vacation to get away from stress. Not to deal with more. Will hold off for a short time and eventually decide.