beginner looking for upgrade advice, mainly outdoor photos

Size is not a big deal. I would prefer smaller, but not at the cost of sacrificing other features. Also, for the night shots, I know i will need a tripod. Ive been told that the shutter remote is necessary, but not all the cameras ive seen are compatible. Some ive looked at without the remote capibility have had max exposures of 15 or 30 seconds. Is it correct to assume that this is not long enough?

Thanks!