I was thinking, while the kickstand is still down, you could swing your leg over the top tube, but I guess the kickstand lifts the bike, making that even more difficult.
I think if you pay attention to what you are doing, you should be OK even with the added weight. I step onto one of my pedals before swinging my other leg over the saddle, which led to my toppling over, never having found balance on the pedal. If you can get astride your bike without using the pedal as a step up, there shouldn't be a problem. If that is too much of a stretch, walking to the curb should work.