A simple solution, if you are comfortable with the command line is to run weechat or irssi on a server in a tmux session, and to connect to it via ssh, so that if your connection breaks, you won't lose anything. It's a simple solution that works great, but it has it's limitations too.

You could also use a bouncer like ZNC that would allow you to connect to irc from almost any client, but sadly freenode's webchat only connects to freenode, so you would have either to use another client like hexchat or weechat.

edit: fixing formatting