Bump up the temps to 95.
Keep humidity within range. Don't let it get too low because it does dry out the mucous, which can clog up the air ways even more.
Go to the vet. Get a culture done in order to determine what kind of antibiotics are effective. Not all meds will work because there are different strains/types of RI. So it's important to find out which ones will work.
Also, you can also use F10 + Fogger to do an at home nebulizing treatment for RI. Some vets have backed up this method.