A wedding is a wedding regardless of where it's held or how many attend. It's just a case of choosing a venue and how elaborate of a reception you want to have. Check into nice gardens or restaurants that have a nice room or garden where you can get married. Some inns have lovely reception rooms where you could have the ceremony and the go into the dining room for a reception. The reception could be a sit down dinner or champagne with hors d'oeuvres which could be a combination of hot and cold ones. Wait staff could be circulating offering these to your guests while some other wait staff are ensuring that everyone has a glass of champagne or other beverage. You would want to ensure that your guests who do not indulge in alcoholic beverages are taken care of as well. Have a wedding cake to cut and have that passed out to your guests. This would not be a long reception, maybe two to three hours and it's over. You could opt for a wedding in your backyard if your garden is particularly lovely or that of a friend or relative. Same thing with the reception, have the champagne and hors d'oeuvres with the cake. That's it and it's over. The smallest and most simple would be to have the wedding at home and have cake and beverages after the ceremony. You would be looking at three hours from start to finish.
It all depends on how much money you want to invest in the reception and how simple of a ceremony you want to have. Personally, I would have the wedding at home, serve champagne and have the hot and cold hors d'oeuvres, plus a few stations where there is a cheese board set up with appropriate crackers and breads and fruit. Later, I would cut the cake and serve it. This might run about four hours from start to finish. That's long enough with people there for the ceremony and then having the room transition into the reception for the guests. The main thing is to make it a day that you will remember and to not let it get out of hand. Sometimes when planning a small reception, it kind of grows beyond what you had initially thought it would be and becomes a huge headache. Don't let this happen to you! Classy but simple is the way to go.