Even the onboard compressor won't fill the tires, even those on Semis or at least Freightliner.
I'm not sure how they determine the pressue they put out but it is not logical since a 125 lb pressure compressor wont fill a tire to 110 lbs or even 100 sometimes.
They make an air doubler. Ives seen one on the Internet,a little pricey. They did come installed on Newmar. I've seen small 150 lbs compressors with twin tanks but they quite making them. You should have plenty of ac power on board and at least a couple, of compartments with ac plugs. It does take up valuable space to store one that is capable. The air doubler or pressure doubler can be installed in the compartment where the air compressor chuck is. There is plenty of room in ours.