Sure, it’s possible to work hard and play hard in college, but how much you can handle depends on you. Being pre-law doesn’t add anything to your schedule because it just indicates that you want to go to law school, not that you have to take extra or harder classes or anything. You’ll be more stressed when you have to take your LSAT but that’ll only be temporary stress. Double majoring just means that you have more requirements to meet, but that doesn’t necessarily mean that your classes are harder or that you have to overload on your classes. But, of course, that depends on what your double major is. But if you enjoy both majors and your good at both majors, then it shouldn’t be that much more difficult than a single major. Make sure you make a four year plan to figure out what classes you would have to take to graduate on time. You may find that it’s way too much or you might find that it’s totally manageable.
After your first semester, you’ll get a better idea of what you can handle.