They're too young to imagine anyone not having anything better to do than go to work, so they have no sympathy for you. And they want you out of their shop so they can go back to making fun of you and hit on each other. Luckily their humphs and glares are no more effective than the ones you've become immune to in your own teenager or crowds in airports wishing you'd give up the choice spot on the floor, leaning against a column with a power outlet right next to you. Forget them; they'll learn to deal or their batteries will die. It's the law of the jungle.
Cell networks are a second option, for phone calls and tethered access. With a me-fi connection, all you need is a power plug. Cell nets are just as vulnerable to hurricanes as anything else. If a couple of towers are out from the blackout or storm damage, the cell you settle in could run out of bandwidth quickly. Keep an eye on your bars; if you disconnect more than a couple of times in an hour, move on.
After 10 a.m. the crowds stream to libraries, blessing Ben Franklin for free access to more good seats, lots of power outlets and blessed quiet.
By 10:40 "server is not responding." Library WLANs weren't designed to keep up with a couple of hundred road warriors at a time. Email and text messaging works because they can download data and stop.
Browsing or anything that needs constant connections and work like a dream even on tethered cells or other low-bandwidth connections turn into frozen honey. Nothing digital moves without a long wait.
Eventually Librarians become testy and dangerous. If they wanted to stand at a desk and answer the same question over and over again for increasingly annoyed customers they'd work airline check-in counters. They don't really appreciate the innovative thinking behind calling the front desk on your cell when you're at the back of the line, just in case you can reserve a desk or wired connection or something. Customer-service people at the airport don't like that, either, but they're trained not to overreact. A librarian will keep trying to seem helpful right up to the second before it becomes necessary to kill someone with a staple-binder.
Try not to be that person.
When it's time to flee the library, try bookstore/coffee shops. Their bandwidth is higher and there are fewer seats than the commute'roid shops. By the time you're done with the library, the first couple of waves will have filtered through the bookshop and a couple of squishy chairs will be open. All the good pastry will be gone.
Don't push things too far. If you've been hop-scotching around the no-power zone all day to keep ahead of the crowds, you've spent more time looking for wifi than you have working. Don't make the ratio worse. Go home.
Sign your cell phone up as a me-fi station and tomorrow work from someplace you can get a working plug and cell connection.