Can I keep using my outer tube tyre with a hole in it

I was riding down a nice smooth bike path the other day (at speed), and there was a branch full of thorns about 10m ahead of me, straddling the path. I couldn't have gone around it. One of the thorns pieced my tire, and pricked a hole in my inner tube - which slowly deflated. I will replace the inner tube - but is it worth me buying a new tire because of a 5mm hole from a thorn? Will this hole expose my inner tube too much? Thanks