I'd start by talking to the state. That route should be no cost. Find out NOW if this will be OK.
Can you get the county to spell out how many hours/minutes of instruction happens? I'm in PA & the last page of the IEP lists out total hours and how many are sp ed versus gen ed. Can you get the county school to do this so when you transfer schools, the new school has to justify the cut in instructional time? If they are cutting out 2 hours & 50 minutes of time that students are there, they need to show they are not cutting out instruction. (And kids that age need breaks. They can't go 4 hours w/o a break/recess/snacks.)
They need to show that the change in ratio will also work for your child. Again, spell this out in the current IEP so the new program is the same. My gut says you're going to need a lawyer but talk to classmates families. You should be able to do something that's class action ad where the district cover attorney costs. Or contact your state's disability rights group or ed law center.