Cobalt -
Here's a blended approach: As has already been stated, come up with your own estimate (based on feedback here from others and your own thoughts) then go on the high side. Continue to reevaluate your guesstimates as you move towards retirement as your mindset and perspective on things will perhaps change (ex. maybe you don't golf now but as you get closer to moving to TV, you can see yourself doing that). The blended part: Once you pull the trigger and retire,
stick to that amount.....somehow.....any way you can. It becomes a give-and-take approach - maybe you underestimated in one particular area.....you can cut back in another area to offset it. But the main thing to do is manage yourselves to that budgeted number as best you can. Obviously, nobody can foresee some unexpected circumstances that can throw a wrench in things. But if you've done a good job of addressing your #4 (stashing away some rainy day money), then you should be fairly well prepared for changes in circumstances.
Also, build some reasonable annual inflation/cost-of-living factor into your estimates.
JMHO
Bill