Consider getting a small 120V compressor, like the Husky or Porter Cable, et.al. If you're filling before a trip or before leaving a campsite (not a boondock), that will get you 110 psi reasonably quick. I use my 3 gallon Makita air compressor (runs my air nail guns, hobby WW'ing) to fill up the tires. Although it fills its tank to 120 psi, I need to dump air until it kicks on again and then connect to the valve stem. Takes me only a few minutes to get the tires up to pressure (110 psi).
Save the 12V compressor for road emergencies or where you don't have shore power.
PS: When checking the tires on the trailer, don't forget the spare. You might find it useless if it's hung there neglected for a couple years. Unfortunately, the stem is on top, so you do have to drop it. I suppose you could flip it over, though.