Really new to these so a rather basic question.

I have a grafted Adenium which I received bare-root and leafless a bit over a year ago and planted in a 4 inch square pot. It did not go dorment this Winter and has grown rapidly, it has 3 main branches about 6 inches long, the caudex root arch is now well over 5 inches, and it is splitting the pot.

How big a pot should I put it in and is this a good time to repot it? It has not yet restarted active growth but is still densly covered with leaves.