What is the lifespan of a 2009 Honda Accord v4?

It has 110,000 mi on it. I'm afraid the car will shut down on the highway

If the car has been properly maintained and it drives well with no apparent faults it should be good for double that mileage. Honda make very good cars. If you are worried about breakdowns join a breakdown organisation. It's AAA in the US if I recall correctly.

Honda engineers some of the best quality engines on the planet. As long a Honda is well and properly serviced and maintained it can easily last 300k miles or more. Has the previous owner properly maintained the vehicle? If they have they should be able to show you proof of all service and maintenance receipts.

Just buy a AAA membership for about $65 a year. As long as you have a cell phone with you, it does not make any difference if you break down. A wrecker will only be a few minutes away any time any place and any day.
The tow or fix is free and wrecker guy usually throws in a free ride home.

It should go another 100,000

My nephew owns my parents' old 1999 Honda Civic and it is on its 3rd head gasket and still going.

The FIRST thing you should do when examining ANY used car is to open the glove box and look for the death certificate attached to the inside of the glove box door. If you find one, it will tell you EXACTLY how many more miles the car will go before it dies. If you DON'T find that certificate, it means that NOBODY knows exactly how long a used car will last. It could run for another 100k miles, or it could blow up in your driveway tomorrow morning.

There's no such car. V4s are found in boats. You should be able to go for another 40k miles before parts need replacing.

If yr honda sounds like an old banger, buy a nissan