Tell that to the Vikings then. Their ships were not designed for long open ocean travel, but somehow they managed to carry Lucky Leif all the way to the New World. Of course Lucky Leif did have some help with the fact that Norway to Iceland - you have Scotland to stop in; then Iceland to the New World - you have Greenland to stop in.
The Romans can in theory get to the Canaries, but why go to the New World in the first place? At the time the Pharaoh's canal was still in operation - going to India, Vietnam, or China is far more useful for the Romans.
Many misconceptions here. First off, Norse shipbuilders were rather more sophisticated than you give them credit for and likewise they were great navigators over open ocean, vikings after all being people who made a habit of crossing the violent North Sea. Secondly, he wasn't hopping from landmass to landmass, Leif Erikson was living in Greenland at the time he made his famous trip to Vinland. And Greenland to Helluland isn't nearly as much of a stretch or a long-haul as from Britain or Spain to New England or the Caribbean.
In any case, a storm strong enough to somehow pull all those Roman ships from Europe to America is a storm strong enough that at the very least most of the Romans would be dead. People on this site have for years had the bad habit of assuming transoceanic voyages are as simple as being pulled adrift by a strong wind with no regard to rations, seaworthiness, navigation (these people are never finding their way back), and wind speed. Most likely the storm drops them more towards the middle of the Atlantic, the Romans have literally no idea where they are, and they either kill each other in mutinies or die of dehydration.