Yes, that's a very wide and dangerous gap regardless of the adhesive used. However, in general, most epoxies have the ability to fill gaps and often require a surface that is roughed up a bit to get a good "bite." The surface can be prepped with 60 grip paper, a hacksaw blade, etc. On the other hand, the TiteBond glues requires a very smooth mating surface...NO voids and no rough spots to "get a bite." They do not have gap-filling properties.
TiteBond releases at 150 degrees F. You can use a heat gun to GENTLY heat the wood until it comes loose. Best of luck.