Once upon a time, before society magazines and bridal shows made people think otherwise, a 'normal' wedding would take place in the morning, at the local parish, usually on a weekday (when the clergy had free time) and was followed by a 'wedding breakfast' often provided by the church ladies or the bride's extended family. Everyone wore their regular 'Sunday best' and wedding presents were rare, given only by very wealthy or very close relatives. The guest list was either 'the parish' or the couple's parents, best friends and siblings --like 40 people, max.
No decorations, no 'entertainment' and no expectation of 150 people being fed, wined and danced in some fairy tale castle until the wee hours. Of course, much of what happens at weddings today wasn't done by royalty at gala 'balls' 200 years ago. Or, rather, the kinds of things that happened at balls have all been collected together and now couples are expected to re-enact everything possible, all in one day, all at tremendous expense. Why?!?
Fresh, local flowers that are not 'arranged' by professionals make nice decorations and bouquets --they are a lot cheaper than exotics and anything a pro wrote 'wedding' on. There is something about the word 'bride' that brings out the dollar signs, in many industries. Even party planners tend to add 50-200% to their prices just because it's a wedding, not a retirement or birthday. Which is ridiculous, but apparently a great many people are going along with it.
If you time the wedding and afterparty for between obvious meal times (like wedding at 1:30, party from 2 - 4:30) people will not expect to be fed, or fed much, and you can just do the cake thing and leave.
Remember, this isn't your Princess Day. That was your 5th birthday. This is your 'I'm an adult who can be fiscally-responsible' celebration of the beginning of your marriage. There is no reason to go into debt for this, not the least because debt is a bad place to start a marriage!