Shapp, We launched on the MF the day after you. Water was a little low for our tastes, but no one really got stuck. I think my wife and I had to shift around on the cat in Ram's Horn or some place to dislodge ourselves. Great weather!
My wife and I do may 1 boat trips. Our first time down the Main was a 1 boat trip in early July about 5 years ago. We did a one boat trip last year on the Main and it was just as much fun as the first time. She will sometimes paddle her IK. We thinking we want to do a solo MF and GC one of these days. It's so easy when it just the two of us. Food is easier. Dishes are easier. Camps are way easier. Sometimes a sweet looking sand bar is perfect for us.
We also bring the big cooler, since we prepare a lot of frozen meals before hand and eat lot of fresh meals on the river. When space developes, we start adding beers to the cooler. We have taken a look at our gear and started paring down some of the stuff we bring. Mainly to reduce weight. We're big fans of the rectangular kitty litter buckets for carrying charcoal and firewood. They're light and a good shape for packing into the drop-everything-bag. They're good for carrying recycling and trash out afterwards.
FWIW, we can get by on a 5 lb. propane tank for 8 days. We do cook a lot on the grill. Breakfasts are the main use for propane for us. Coffee and oatmeal or egg scramble or pancakes.