Heel slides are fine, but don't use a device to pull your foot backward, just slide your foot yourself and only do a few a day. Definitely give yourself a week, but if you go back to aggressive therapy you may go backwards, so be careful. Your pt doesn't sound like he's going to change the way he works on you. We don't buy the first pair of shoes we try on, we shop around to find the best product, so do the same for your knee. While you're resting/elevating, research other pt groups if you feel you need to go to PT. Call the offices and ask if they give non-aggressive pt, but lots of people do just fine with no pt at all. You are after all just a month out, I gained ROM months to a year after my TKR.
Ice, elevate, rest as if it's your job. Try toes above the nose a few times a day.