I would be arriving in LGA at 4:25pm on CO from IAH (already booked), is it enough time to connect to a US Express flight that leaves at 6:10pm to BUF?
Was originally supposed to stay in NYC, but looks like now I will be going straight to BUF

These would be seperate tickets, but I assume CO would interline the luggage.

What happens if I miss the flight, would I be SOL, or would US allow me to standby (even for $25) for a later flight that evening.