If I understand the math correctly, my set up is probably at the high end of the range for acceptable weight.
Trailer is 26ft, 4900 lbs dry, say 5500 lbs loaded
Toyota max vehicle + trailer load is 12000 lbs per the manual, page 314
T4R curb weight is 4224 lbs, maximum GVR of 6005 lbs
add 700...