Boat in colder weather
I would also recommend bringing a shovel with you, spud bar if you there is ice on the lake and a big tub of sand or kitty litter. It is easy to get stuck on a landing and it is very slippery if other boats have launched before you.
I also will warn you that with a bunk trailer that has carpet, it will hold water (AKA Ice) between outings when below zero. Be prepared for boat to slide completely off trailer once you unhook it.
I push things as late as possible so I'll bring an ice chisel along in order to break up landings that have skimmed over enough. I'll also toss a couple bags of barn lime in my truck in case a launch has frozen water on it.
After using a boat all summer long some compartments might get a tad disorganized. Once that first frost hits I'll go through and straighten anything out. It sucks having to fumble around with disorganization wearing heavy clothes in 30-35 degree temps.
I make sure I have at least one extra rope along because conditions can get pretty darn sketchy later in the fall. A couple of years ago I tied that extra rope around my waist and to a pair of boat cleats because it was so windy. Didn't fish too long that day but the thought of falling into 40 degree water wearing ice fishing clothing prompted tying myself off to the boat.
Those engines are as reliable and low maintenance as you could ask for.