Since the new stadium updates, along with Titletown next door and the updated (much larger) Resch Center on the other side taking up more space, parking for ~80K fans has become difficult at best - even the surrounding home driveway/front lawn "lots" are pretty packed. Now try parking double that many people (I've heard they expect 150K-ish fans). Plus, instead of two teams' reps, you have reps from all 32 teams - that's even more people to have to account for. And instead of one TV network, there are (at least) two that have a serious presence at the draft. That all adds up to a LOT more people trying to get to the stadium.
And you don't have a lot of hotel rooms within walking distance, and GB public transportation is next to nonexistent. Just getting that many people to and from could be a logistical nightmare.

And that's not even considering restaurants, gas stations, etc. suddenly having twice the number of people to serve. The capacity for EVERYTHING around that stadium will be stretched to the absolute maximum...

And this isn't a six-seven hour game day experience. This is the entire weekend - Thursday night through Saturday afternoon.

Just saying that logistically speaking, Green Bay isn't built for this at all. I'm sure they'll figure it out, but I'm thinking if I lived in/around GB, and I wasn't planning to attend, I'd probably plan a vacation elsewhere.