If you’re looking to not move all too much, you could do Hangzhou as a day trip, head to Huangshan for a few days if it interests you, and maybe stop in Xiamen for a night on the way down to the GBA. If you want to move around a lot, sure, you could go up to Beijing and do the Great Wall (though I’d recommend a longer trip for Beijing, there is a lot to do). You could also head out west and see Zhangjiajie and Chengdu, with maybe a night stop in Chongqing, before flying to CAN or SZX or wherever, which is what my recommendation would be.