Geoff, I was on a European trip back in thd 1980s and broke a tooth off, it was a porceline crown. I went into a shop in Amsterdam and bought some Superglue (which had just hit the market). I glued the crown back on the stump of the tooth and it held up just fine until I got back to my dentist in Canada (who just laughed at my DIY approach. Obviously you don't put much pressure on it, but it can be temporary fix, and don't get it on anything you don't want glued (like your tongue).
