There is taking a leave of absence and then there is withdrawing. Also if there is a financial aid consideration you’d better find out about that. If you withdraw you have to reapply and may not be readmitted or given the aid you had. Graduation requirements are subject to change. If you change to another school, your credits may all transfer or some may not. They may have other graduation requirements you have to fulfill.
You do have summer to travel. And winter break. In order to study abroad and get credit your school has to approve the program. You cannot pick any program and you college will accept the credits. However many schools have long lists of programs they accept credits from. At Brown, there are Brown programs and pre approved external programs and you can apply if the external program is not on the preapproved list. Here is what mine did. Study abroad in external but pre approved program in fall. Leave early to visit a neighboring country (friend’s home) first. Attend program, do a couple long weekends in neighboring countries. Travel for 3 weeks at end of program over Winter break.