TwoSix
Everyone's literal second-favorite poster
Definitely doable. Or to make it even simpler, you can leave the spell progression alone and simply truncate class spell lists at level 5.If we are using spell points and only have spells to level 5, but at later levels you could only upcast lower level spells to levels 6-9 that could be interesting variant.
just reduce spell costs of levels 6,7,8,9 from 9,10,11,13 to 8,9,10,11 as upcasting really sucks.