Problem with the championship is the number of games. 46 games is a brutal number to fit in over a season. Plays havoc with training routines, impacts on player fitness. Attritional stuff. Not sure that many of our current squad would have the stomach for it.
But different clubs react in different ways. The yoyo clubs - Fulham, Norwich, etc are set up to cope. Some like Leeds just implode and never come back for years, but I don't think that would be us, as we aren't the same sort of basket case that they were when they were relegated. Some like Villa get the money poured in, a half decent manager and get back on track.
For me, Stoke's first season down looks a lot like I imagine ours might turn out if we are relegated -
https://en.wikipedia.org/wiki/2018–19_Stoke_City_F.C._season - never got a foothold in their first season down despite having "the best squad in the division", too many show ponies and lazy money grabbers not bothered to put the effort in that the league requires, and now properly downsized to a perennial mid table championship club with no obvious way back.