He survived that impact because of regeneration, that has nothing to do with his strength or durability.
He was durable enough to [BLACKOUT]protect the rest of the Guardians from most harm. If he only had to protect himself he could have walked away from that crash. I think Rocket even hints at it.[/BLACKOUT]
Still I'm probably pushing it since I liked Groot alot in this movie. I'd also say Rocket is an engineering genius second to Stark in the MCU. I need more FEATS!!!!!!!!! Really can't wait for GOTG 2.lol