One thing to rule out: is the new pot sitting in a cover pot or saucer that holds water? Peace lilies wilt from suffocated roots in a way that looks identical to thirst, and that is the mistake I made the first time.
Three and a half hours on low is where mine land too. At that point it stops being a leave it all day recipe and becomes a start it at lunchtime recipe, which is worth knowing before you plan your week around it.
If you are handy at all, a heating element on most vented dryers is a genuinely easy job. Two panels, a couple of spade connectors, four screws. The part is often 40 to 70 online with the model number. That changes the maths from 180 versus 600 to about 60 versus 600, and it is a decent first appliance repair.
This matches my experience. The Pi was fine right up until it was not, and by then I owned a shelf full of Pi specific accessories arguing with me about switching.
Mine did exactly this when we swapped rooms, and I panicked and repotted, which piled transplant shock on top and cost me another four leaves. Change one thing, wait three weeks, then decide.
Worth knowing that variegated ones come back plain green from leaf cuttings. Divide the rhizome instead if the stripe matters to you.
A twenty dollar clip on grow light on a timer would change this decision entirely, and would also fix the leggy growth you almost certainly have from a north window. Cheaper than most pots and it makes winter repotting a non question.