The road to the SB Peak trailhead is about how it is every season. Rutted and rocky, but navigable. I’ve seen a mazda miata and multiple prisuses there this year, but you’ll get there slower in those than in a pickup.
a few weeks ago, the trail beyond limber pine was still not broken, though you could walk straight up to san bernardino peak along the ridge from limber pine. not sure how that trail looks now.
on the divide, you’ll be encountering lots of sections where the trail is covered with snow. not really a problem up there, since it’s easy enough to get around them off-trail in most places. Budget additional time for regularly checking to ensure you’re still headed in the right general direction when off-trail.
Unless you travel very early or very late in the day on the divide, you shouldn’t need ice axe and crampons, but that depends on a lot of variables, including the skill level of your group.