If this lost seat is the one that installs Schmuck Schumer as majority leader you may regret that sentiment.
I believe the GOP simply needs to win the Senate races in the states that Romney won in 2012, and hold a couple of others in states that he lost. Rubio's victory today takes care of one of those, so I think that's a good step.
Remember that there were 34 Senate seats contested in this election. Based on how the seats broke down by party line, the Republicans were defending 24 seats and the Democrats only 10. Up until about six months ago it seemed almost impossible for the Republicans to retain control with this kind of challenge defending all those seats, but some of these GOP candidates (including a few who distanced themselves from Trump) ran very smart campaigns.