First - CONGRATS!
Best wishes for you as you and your future husband prepare to become one in marriage.
Second -
I just married in Feb. Expensive seasons vary by location and popularity. For example, here in DC/MD/VA area, peak wedding season runs May - Sep. Those are the months with the mildest weather, you can use facilities that have gardens and outdoors space, getting the most for your rental money; no snow showers, rainy seasons, etc. etc.
For international travel to the Carribean, peak season was Oct - Mar, for the same reason - travel couples with holidays so relatives can attend, its warm there while its cold here on the mid-atlantic states, etc. etc.
Ask vendors what is peak season in the location where you want to marry, and when their rates increase/decrease. Also, ask if they honor special rates for larger/smaller groups, or associations, government, etc.
You will find if you do your wedding when NO ONE else does it - during off peak season - the cost pays off all across the board! Everything is lower. Videographer, cake, florist, etc. Dress sales cause the economy is in a slump and no one has to purchase. And who knows...your weather still may be beautiful...I ended up having a 65degree spring like day and evening in FEB - then it turned 17 degrees the next week! Heaven was smiling on us.
I wish you the best!!