Not too bad, it's only like 6 blocks, but I'm used to walking everywhere. There's another small park only like 3 blocks from the hotel but I think that would be a little cramped for our 40+ people in the Pokemon Gathering.
EDIT: Also to any people in charge of con things that look at this, at Sakuracon they put the time and place of the meet-ups in the schedules which was really nice for people who don't browse the forums or are directly involved in planning it. Do you think this could happen for Kumoricon?