Don't you miss the verbeegs and the voadkyns?
Now I am imagining a mash-up for giants, all the types, mixing Zendikar(Magic: the Gathering) and Cerilia(Birthright). After the comingsoon Vecna event a new plane is created, and then this is settled by the giants. This place can be visited and explored by dragons, but the gegraphy is too inestable to keep their threasures. The settlements are possible, but after some decades migration is necessary, for example when planar gates appear, allowing invasion and raids by planar creatures (mainly elemental monsters).
Some ordinary humanoids can become giants thanks special ways, mainly ruling a domain to "gather" special "primal spark".