You can usually guess which gate it is and get a jump start on the insistence of men as it goes straight from “gate will be announced at 05:30” to “boarding”. If it’s the Embraer you NEED to do that as the overhead space is tiny. Though I think all the early flights are 738/9s.
There’s no way I’d wait to 05:30 with checked bags, especially if you want them checked through. 05:00 latest, especially in holiday season with the likelihood of non-regulars unable to negotiate this week’s security farce.
At AMS the 73x come into D50 or worse, so a long walk down the arm but it’s better than the noddy bus stands beyond B. KLM will try and hold your connecting flight as long as possible. Long hauls usually go from E gates. It’s quite walk, but at least you don’t have to do passport control.