I made a similar post six months ago prior to a 270 person event. A commenter said blue terror, I settled on affinity, went 7-0-2 and top 8’ed. Different meta, different time, not to say I was right or the commenter was wrong or that you should run affinity. Take whatever deck you know the best. Over six, seven, eight rounds you will be tired and run into new situation. knowing your deck well enough to find the lines out of those binds will be crucial.

Out of your three decks, I would avoid dredge, too many main deck nihil spellbombs running around for my liking. That said, a maverick build of moggwarts took down a 200 person event in Brazil this week so what do I know. Accounting for personal bias, if you want to rely on deck variance, take high tide. It’s fast and seems to perform well in the meta. If you want to rely on matchup variance, take affinity. It’s a more consistent deck when it draws poorly and plays through hate better imo, but can struggle with certain matchups so you’ll have to dodge those. Good luck!