Another option is, instead of floating, to set the white-space property nowrap to a parent div:
.parent {
white-space: nowrap;
}
and reset the white-space and use an inline-block display so the divs stay on the same line but you can still give it a width.
.child {
display:inline-block;
width:300px;
white-space: normal;
}
Here is a JSFiddle: https://jsfiddle.net/9g8ud31o/