I'm still not sure what you're asking.
If you want to load data into a partitioned IOT, then you can create a maxvalue partition. And have a process to split this as needed:
create table t (
dt date not null primary key
) organization index
partition by range (dt) (
partition p0 values less than (date'2018-01-01'),
partition pmax values less than (maxvalue)
);
insert into t values (date'2017-12-31');
insert into t values (date'2018-01-01');
commit;
select * from t partition (pmax);
DT
01-JAN-2018 00:00:00
alter table t split partition pmax at (date'2018-02-01') into
( partition p2, partition pmax );
select * from t partition (p2);
DT
01-JAN-2018 00:00:00