Naruto can apparently have only 5 shadow clones gathering natural energy to enable his sage mode. Why not use the following approach?
- Create 4 shadow clones for storing energy and one shadow clone doing nothing (at present)
- When one shadow clone is released, have the idle shadow clone create another one.
- Repeat as long as required
This way there will always be 4 shadow clones gathering natural energy and there will be no limit of times Naruto can go into sage mode.
Please bear in mind that I've not read the manga and have seen the anime episodes till 264.