That's also one of the reasons I edited my post, I never saw it was just the two of you and it made my viewpoint much less relevant.
But if money isn't an object, then pay a pro for a couple of hours, you won't need them all day and you'll get a reduced rate.
It seems irrational and risky to go low budget / free on a non pro for such an important thing when you can by your own admission, afford it.
Also if it's a weekday wedding you should have togs fall over themselves with availability. I did two hours in London last Thursday for £500, which turned into three hours but I allowed for that in the price.
You could even approach some togs asking for engagement shoot prices. The timeframes are similar.