Hi,
Considering your situation I suggest to use repartitioning to create additional partitions for the next 2 years. You don't have to worry about the number of partitions since it is still quite low. Imagine the number of partitions an InfoCube can have in the F-table (i.e. if no partitioning and compression takes place). Normally, a query does not select more than 2 years of data (I suppose it's financial data), so no more than 24 partitions are retrieved.
Best regards,
Sander