rescue is correct
There are 2 historical reasons for children getting long summer vacations:
1) Help with the harvest
2) Hot weather makes learning in school nearly impossible
Helping with the harvest is no longer relevant to our demographic (and may or may not be entirely irrelevant). The second argument is also irrelevant as air conditioning makes the weather outdoors a non-issue.
The reason for leaving the city is not pritzus (though we frum people added that reason) but due to other factors such as:
children playing outside (no school, no xbox) on city streets is unsafe and it is too hot, the city doesn’t have recreational facilities (no longer relevant, they do have), and summer air is too polluted (smog) and unsafe to breathe.
Our air quality is much better in the city due to environmental laws, and again – with the ubiquitous air conditioner there is always a place to escape the heat. There is absolutely no reason to continue giving summers off. But it’s more likely that the Peewee league will beat the Yankees in the World Series than that summer vacation will be cut short.