as if there was no tomorrow
Without restraint; in the most extreme manner (i.e., as if motivated by the fact that there won't be another opportunity). He must have been starving, because Jonathan started wolfing down his food as if there was no tomorrow! Every time Kevin goes out shopping he spends money as if there was no tomorrow.
as if there was (or as though there were) no tomorrow
with no regard for the future consequences. 1980 Guardian Weekly Oil supplies that Americans at home continue to consume as though there were no tomorrow.