If not using two schools at once means that you're more likely to have a long break from flying, then I'd say use two schools. With less of a gap between lessons you'll be doing less skills revision.
It would probably make life easier aswell if you make both schools aware of the situation. Also make sure that your student record is kept up to date after each flight, and carry a copy of it with you so that each school knows how you are doing. Also make sure that you are happy with the instructors you have at each one.