You tongue jack fully extended and the rear is 1.5" low?
If your wheel disconnects, you could stack Lynx levelers to give you more height.
If your wheel doesn't come off, I would take a bottle jack, jack the tongue up level and put Lynx levelers under the wheel.
Then set your stabilizer jacks.
Just thinking out loud.
2016 Toyota Tundra SR5, 5.7 V8