This is a template that I used successfully to capture the high level strategy for 3 different product sets in a portfolio. I have included descriptive text over each field so you may understand what it intends to capture. IMHO, strategy is in essence made up of these parts:
0. Vision (what's your Big Hairy Audacious Goal? What's the bet?)
1. Why you want to do something (why bother solving the problem)
2. What you want to do (what's the problem you want to solve)
3. What are the immediate identifiable obstacles that if overcome, set you on your way.