My friend at 'Active at Altitude' sent me this response. It makes a few useful suggestions, and I post them here in case anyone following this thread is interested.
"Adjusting to altitude - well, as much as the research suggests best practice, each of us respond differently. In theory what you suggest should be helpful, as long as you treat the days at higher altitudes as "very easy" days! In most cases folks start to adjust to moving to higher altitudes after 3-4 days, so the 6 days in total should stand you in good stead.
It is possible it can have a negative effect depending on how your body has adjusted to altitude before? Also make sure you are well rested, fully nourished and hydrated before arriving a higher elevations. Tank Up Fat soluble vitamins (like A and D) will stay in your system after you arrive at altitude.
Take daily amounts of water soluble vitamins (like C and [B)] to help your body cope with the stress of high altitude exercise. Adequate complete protein intake will ensure that your body has a full compliment of Amino Acids to repair itself at night.
Also add additional carbohydrates to your usual meals - your body will be going through additional stress once you start being active at higher elevations, and you will burn more carbohydrates than usual. As carbohydrate is the primary fuel source for relatively intense exercise, it pays to make sure the tanks area full when you arrive! Add 5% to your carbohydrate intake for 5 days prior to arrival at altitude. That's typically around 75 - 100 calories, or an additional banana or 2 pieces of whole wheat bread per day.
Trust that helps mate! Let me know how you get on!"