Looks like I got to adjust my plans a bit: 67 down to North Rim is closed till mid May based on the NP website.
Have been on North Rim in late April, main paved road had "road closed" sign but lots of side dirt roads (good quality, easy 2wd) were open, unsigned and dry.
This was 8 or so years ago so might have changed but was nice and empty, pretty and nice Temps.