A friend & I did a very nice loop in SW Utah out of St. George. We flew to Las Vegas and took a shuttle from the airport to St. George. The shuttle took bikes, but I have no idea if it still exists. Anyway, our route passed through Enterprise, Cedar City, Panguitch, Bryce Canyon NP, Zion NP, and back to St. George. We did it in late May. It was hot in St. George, it snowed at Cedar Breaks, and was just right at Zion NP. The climb up to Cedar Breaks is significant, but I don't recall it being extremely difficult other than the snow squall we encountered on top (not unusual, apparently).