There is an additional school of thought on the subject of how long I can tow. This website covers the method Leon mentioned and then goes on to explain that this particular standard accounts for the "vertical" effect that a regular trailer has on a vehicle. Because a Trailmanor is closer to the ground (folded) it does not behave completely like a trailer but rather exhibits some boat like qualities. Check out the section on distance from coupler to rear axle vs your wheelbase. You'll need to check with Trailmanor directly or someone here can tell us the particular dimension from couple to rear axle on a 3326.
http://www.rvtowingtips.com/how-long.htm
I not saying this to change the laws of physics. Just pointing out that there "may" be other options.