You can DIY "hard wired" but it will be a bit of a science project.
You will need a 4–20 mA temperature transmitter, a compatible sensor and a display module. A "current loop" setup like that is immune to line resistance out to the sensor, so it is good for the distance you're talking about, (Within reason: you still have to size up the wires a little as distance increases or the transmitter won't be able to shove 20 mA thru them.)
If you are feeling your inner geek and want to try it,
these people can supply you with what you need and give you tech support.
