Go after pesach. From what I’ve heard and read, its virtualy impossible to have the hotel keep the same level of kashrus you would provide yourself at home when they are catering to a huge crowd. Mistakes happen.
No, they don’t serve bread by mistake. But bishul issues, wrong cleanser being used, a “not as frum guest” bringing in his own food to the meal, and using the house dishes (which then go back to the kitchen and into the dishwaher with the other 499 plates, which then comes back out as YOUR plate).
Besides, no matter where you go, you are looking a staggering cost of $1500 – $2500 per person. All this to fress, day and night? Is that what Hashem took us out for, to be his chosen people?
Go after Lag bomer without the guilt and almost definite kashrus pitfalls.