when flat towing you MIUST take into consideration bends in the road, road conditions, substantially poorer braking, great loss in power, stress on the tow vehicle.
i have flat towed rigs for about 6 years. i have used cruiser towing cruiser, F250 diesel towing a 60. the F250 being much heavier and having stronger braking and better power was an easy tow. i towed a 60 at different times from Calgary to Colorado with zilch for problems. i towed a 74 with the 250 and darn near lost it twice in one trip due to icy conditions. i towed a Nits behind a HZJ75 and almost lost it a few times on ice, the dead weight on behind pushes you around the bends in the road. i have towed a lifted and locked FJ45 with a HZJ75 with no problems for 6 hours. i have "B" trained a cruiser and a SOA tent trailer behind a 250 with no problems for hours at a time with no problems at all.
it can be done but do NOT drive when tired or distracted, it only takes a second and you will be in the ditch or facing on coming traffic. you need to concentrate ALL the time, it is easy to get lulled into a false sense of security and bang something goes wrong.
BTW when a tire comes off the flat towed vehicle it can get interesting quickly.
i fould recommend borrowing or renting a larger vehicle to tow with.
i hope this all makes early morning sense.
cheers