I would say that yes it would work. The bugbear may not remember anything more than it did then, but it will be much more able to make connections and extrapolate from what it remembers. It won't suddenly remember new things but will be more likely to provide reasons as well as a recount of events. Also some details which were not included in the unenhanced recount for being irrelevant, may take on new meaning and be inculded.
As for making and executing a plan, I would rule you could create a plan and then carry it out after the spell effects wear off but you'd find it difficult to explain or modify. The plan would have seemed like a good idea at the time, even if you don't know the answer now.
As for making and executing a plan, I would rule you could create a plan and then carry it out after the spell effects wear off but you'd find it difficult to explain or modify. The plan would have seemed like a good idea at the time, even if you don't know the answer now.
