Re: sleeping for long stretches
I wouldn't worry about pumping at night unless you either need the milk to build a stash or if you are getting uncomfortably engorged. Your supply should regulate so that it is available when baby wants it, meaning you'll produce more milk during baby's usual feeding times and less during times when baby doesn't nurse (like at night). Then when a growth spurt comes along and baby starts waking to nurse more at night it will build your supply back up as needed.
If you start to notice a drop in supply during the day you might want to add in a pumping session to keep things up, but you are probably getting to the point where going longer stretches at night won't affect your day-time supply.
Oh! Another concern might be if you are planning to go back to work or something. In that case you might want to keep your supply up at night in preparation for baby wanting to nurse more at night once you are gone during the day.
“We are not put on earth for ourselves, but are placed here for each other. If you are there always for others, then in time of need, someone will be there for you.”