The $500 upgrades on the October CLT to LGW in October should be very possible. Just make certain that you call 23:59 minutes before your scheduled departure time. In fact, you may get lucky and get a flexible agent if you Start calling at 25 hours before. The return should be even more possible. If you decide that $1000 each way is beyond what you want to pay, check in at CLT and get your boarding passes, but don't board just yet. When you notice that most of the passengers have boarded, go to the desk and ask for the cost of an upgrade - throwing in the "honeymoon" trip purpose. They MAY offer you 2 last minute upgrades at less than $500 if there are unsold Envoy seats. If they still say $500, just say that you thought it was a bit less and that $1000 would unfortunately require that you reduce some of your wife's hoped for honeymoon land arrangements, so you'll have to pass this time. Obviously you need to make certain that you have sufficent time to get the upgrade processed/or not and still board by the required door closing time. I would suggest that you consider Not attempting to get a "free" upgrade at the gate and then after rejection, inquire about a hoped for reduced price one.