Benefits won't just stop completely. If Congress fails to act, SSA will have to cut benefits to 70%. So, instead of $2,600 you'll receive $1,820. At 70% payout, SSA can continue to pay benefits at projected income levels indefinitely.
Inflation won't be an issue. The only costs going up are healthcare and college. College won't be an issue for you, and Medicare should fill the gap until the US makes it to single payer.