If you split now and let them raise their own, you'll not get a laying queen going again for up to 4 weeks. During that time, bees are dieing and no new brood is being laid to replace the dieing from old age. Then of course it will be three more weeks after the queen does start laying before any new brood is emerging to replace those that have died, and you get three more weeks of bees that died in addition to the 4 weeks that died waiting for a new queen to lay. So, six to seven weeks of dieing bees with no new brood coming. That's a great population reduction. Plus, it'll be the end of June before you get any new brood, or later, if you made your splits today.
Place your order now for new queens. Make splits with new queens in the end of June, you'll have much stronger hives to split from and may have some honey to put on your table as well. This instead of splitting now and letting them raise their own makes much more sense to me.