Somewhat unexpectedly, [1] which is based on actual university research, reports the opposite: Figure 9 says people who had more guests at their wedding report better marriage outcomes - even after controlling for income, education, race/ethnicity and religiousness.
Of course, if you want to discard the research and stick with your anecdotes, it was partly funded by a charity founded by a guy who believed in 'strong families'.
You'd probably want to control for wealth to get good data. Marriage duration is correlated with wealth, and wealthy people probably spend more on everything, weddings included.
[edit] nevermind, the the posted link claims the figures are controlled for several factors, including income and education, which both correlate with wealth.
