Plugging a TV tire

Sure this has been discussed in some other thread, but I can't find it.

My TV has an almost new tire with a big nail in it and a leak. Will plugging it (from the inside) make it good enough? The nail is right in the center of the tread, not in the sidewall.

I really don't want to replace the tire as they're pretty mediocre, and I was hoping to just wear them down and then get something better. And I don't think I can get much for them as a trade-in, especially now.

Unfortunately the spare can't be used as a replacement as it's a different rim size (argh!)

But if it's not safe for towing, I'll replace all 4 tires with something better but that's a really expensive option.