My buddy's motorhome burnt down while on vacation, he was in Pennsylvania at the time, but lives in California. Fortunately he did not need a 'repair' but replacement, and that could wait until he got home. He was towing a Bronco II and had to pack what he got out of the RV into that (him and his wife, her purse, no wallet or any clothes). Lucky for him, he was able to disconnect the Bronco before the engine fire spread to the back of his RV.
He bought a Country Coach after that, and has had great luck with it. . .
You are lucky that you where close to home, and have a good repair shop nearby. Chances are that if someone out of town needed a 'quick' repair, they would have a mechanic pull off another job to get them back on the road, or at least warn them 'we can not look at your refrigerator for 2 weeks' and send them down the road. .
It does sound like they will need to order new sheet metal (or fabricate it) for the wheel wells, and do extensive repairs to your RV, as well as drain all the water and winterize it. If you have another local RV repair place, you can check with them about making the repairs, and see if they are less busy. Chances are a very low cost repair place does not find enough mechanics because they are only offering $15 an hour wages, but a place paying a decent wage can find enough mechanics, and will get the job done sooner. .
Good luck with your repairs. You can always look into renting a motorhome if you did have another trip planned, but that might be expensive and probably not covered by your insurance. . If someone had wrecked your RV and made it un-usable, then you could rent a RV and they would have to cover that cost. But because the person leaving the metal in the road will likely never be found, you are out of luck there.
Fred.