If you want to keep KP happy, there is no trading Willy. Period.
You can trade Kanter, depending upon:
* how the season unfolds, are you in the playoff race come trade deadline
* can he keep up this level of intensity
* can he learn to play smarter D, avoid mental lapses
* can you get back plethora of assets for him
OR
You can trade KOQ, depending on:
* whether the return is adequate
* your assessment of locker room chemistry hit
Unless you consider trading KP for two first-rounders, as suggested here earlier, Willy is untouchable.