The ride itself shouldn't be a big problem with an early start. I would recommend riding up Co-145, Co-141, Co-90 and Ut-46 and then US-191 into Moab, 205 miles. Then return on US-191 and US-491 back to Cortez, 115 miles. Total 320 miles. I would however advise choosing either Arches or Canyonlands and not try to do both. Both parks require three or more hours to enjoy the visit. US-191 and US-491 are both major highways and if the ride runs late it would not be a big deal running after dark.

Just my opinion but I ridden the area for years.
Az Wingrider