I travel to the Moab every year in late March and early April and never have a problem. That being said you very well could run into a snow storm that would impede your travel plans. In that case you might have to spend an extra day prior to coming eastbound over the Eisenhower Tunnel. You definitely will not be able to travel over Trail Ridge road that time of year and probably not until the last week of May or even into early June. Most high altitude campgrounds do not open fully until the last week of May or first week of June.