Bear in mind Ds3, that the published speeds for any aircraft are selected with a margin, where there is doubt about controllability. One of my project required reducing the best rate of climb speed for a highly modified Caravan by 7 knots. To support that, not only did I have to show the climb performance, but also land back from 50 feet after an engine failure after takeoff, and Fly a complete circuit at 5 knots slower than the book speeds I proposed (so takeoff, circuit approach and land at 75 KIAS). Those two requirements were much more un nerving that the more than dozen spins I had to do in it!
There are margins built in to the numbers. If you get airborne "below" the speed, and are climbing, you will continue to. However, if it quits, your chances of entering a good glide may be very reduced. That's why full flap takeoffs are not approved, not 'cause the plane won't do them!