Check their loyalty program. I signed on for Fairmont's program online the night before check-in and saved around $14/day on internet access which is free for members.

We never stay at a hotel without signing on, there's always a benefit, even if it's just late checkout privileges.

In any case, at least in North America the midrange properties always seem to have free access, it's the premium properties that charge for it.

YMMV