BeerBorg

My Belgian Pale has been in the fermenter for 18 days. Very likely finished. I used 3787, Westmalle, notoriously reluctant to flocculate. I have no ferment fridge, but an insulated trash can and a Cool Brew Bag. I'm thinking a cold crashing with ice in those coolers, maybe one inside the other. Or should I just keg it carefully and let the trub cloud the first couple of glasses?

I don't know about kegs, but FWIW, I bottle 3787 from under Krausen all the time without cold crashing, because the Krausen often sticks around for 3 weeks even though its long done. I get clear beer anyways after it sits in the bottles for 3+ weeks. And I don't get a huge amount of bottle trub either because lots of stuff is stuck up in that krausen.

Yup, keg it... If you don't like the trub just toss the first half a pint.

I don't think you would be able to get it cold enough (32-34F) for long enough (48 +- 12/24 hours) in the cool brew bag. I would just keg and with the cold temps it will clear up but take a few extra days.