Investment Advice

I’m 27, have approximately £1.2 million to invest, own my home outright, plan to keep a three-year cash reserve, and I’m considering an 80% FTSE Global All Cap / 20% Global Bond portfolio. I also have looked at just investing 100% into Vanguard’s new LifeStrategy Global Equity Fund to make things easier but I worry about losing flexibility with this. I’ll also have rental income and may do part-time work. My plan is to spend from cash and only refill it annually. Has anyone here used a similar strategy? Is there anything you’d change?