So I truly don't mean to be condescending, but have you handled 20" adjustable pliers like this? They're almost gag-gift comically large for most automotive and household plumbing tasks.
For decades I've had some 16" Channelocks and those are far more practical while still being "large."
Only recently did I want something bigger to try to twist the plastic caps off water/chemical totes (the same thing propylene glycol comes in for de-icing planes) and I opted for the Doyles from HF because 1) I'll likely use them once every four years and 2) anything that
large is going to be relatively low torque OR other methods are coming out like pipe wrench, blue wrench, welder, air hammer, excessive profanity
https://www.harborfreight.com/20-in-high-performance-groove-joint-pliers-64460.html