Modern tires that are not worn out and have enough air in them are rather dependable. I would not bother with a spare or a patch kit unless you have practiced and comfortable using them. In the unlikely event you have a problem roadside assistance is usually fast and safe. A couple days ago wife ran over a chunk of metal that tore a good size hole in her tire (first time in 25,000 miles) and roadside assistance had her home with a new tire on in an hour. Sure occasionally there are longer delays but most likely nothing will happen and if something does you will probably get it resolved in a couple hours.