Depends. If, for example, the forecast for Monday before Easter weekend is looking good, we might decide to take a long weekend trip to a favorite place and just do it without a second thought. The $20/night to camp isn't going to break the budget and will offset by the less expensive food we eat during the trip.
If I am planning something more elaborate that requires long distance travel, I will keep the future, abnormal expenses (e.g., flight, bike shipping) in mind and try to conserve a little here and there (e.g., going out to eat less often) to offset them, at least a bit.
I don't have a wife or kids and my mortgage is my only debt other than my utilities and credit card bill, which get paid in full every month, so I have flexibility in that regard.