Geotargeting to omit a specific area

I have a campaign running which is targeted at a specific selection of cities and working fine.
I want to expand the campaign to national But keep the original campaign running as it has highly specific ad text that relates to the target cities and is giving a really good response which I don't want to dilute.
What I need is an option to exclude certain cities from the national campaign but this doesn't seem to exist. I tried targeting all cities except the ones used for the original campaign but Google will not let you target more than 100 cities.
How do I target most of the country but exclude a specific area?

 

Don't set up a national campaign. Set up multiple state campaigns.

 

This does not solve the problem. I am in Canada and need to omit the greater Toronto area from Ontario. Even if I do a separate Ontario campaign there are more than 100 cities listed for Ontario (more like villages most of them but none the less why cut anyone out of your potential market). Alphabetically I can target all towns in Ontario up to about F before google stops accepting any more. On the balance of probabilities this means that I am missing somewhere around 75% of the province.