I'd say search for all the discounts you can.
Join mypoints and start earning those gift cards you can use them to pay for little things along the way you can probably earn upwards of 200 each if you both sign up for them and work on it now through the summer.
Thats 400$ right there for gift cards like cvs, starbucks, rainforest cafe etc.
look into any discounts you may qualify for with disney or that you can purchase tickets through:
-are either of you in the armed forces if so go to affvc
-are you students some student life offices have travel dept or offer discounts on vacation.
-aaa memberships
-do you know anyone who owns a
dvc can you buy off of them for a discount
-check out sites like skyauctions
-consider staying offsite
when registering for your wedding add
disney store for disney dollars
look at other places to squeeze money from compare rates for your auto insurance (I just did this and actually saves like 600 for the year by switching to geico and getting exact same coverage plus a few extras)
do you have stuff you dont need anymore ebay and save the money.
Do you have extra time run a few odd jobs for some extra cash it sounds lame but I bet a friend has a kid they would love someone to babysit for or a dog that needs sitting while there on vacation its little stuff but it can add up over the course of a year and not take alot of your time.
make some minor lifestyle changes
example: not saying you do any of these but if you do you can save a serious chunk of change over one year doing any of these
dont buy coffee out in morning
limit how often you buy lunch during work week
Carpool
give up car and take public transit you don't have to sell the car just garage it you'll save money on gas insurance and get killer thighs from all the walking. I had a much better figure when I didn't' have a car lol
eat in more often keep dinner out special and make dinner in special
I just saw a posting today for cokerewards that you can earn universal park tickets keep eye out for stuff like that
have a joint yard sale if you haven't moved in together yet Im sure there's tons of stuff your not going to need in new house together and if you have well Im sure you accumulated some stuff you'd like to get rid of.
Either way your off to a good start asking for advice and honestly I hope something helped I remember first big trip to disney and it was expensive but you should weigh your options well like maybe you stay onsite but dont rent a car and use disney transportation then you save on gas and rental or stay offsite and rent a car and you'll save on the room. Just definitely check out the boards and call around to work numbers out.
Regardless I'm sure you'll have a wonderful honeymoon and congratulations on your engagement =)
remember to do all the free romantic stuff like watch fireworks from poly beach i know theres lots of postings about stuff like that =)