Welcome to WKC.
If there's any smoke wood used at all, the glass will turn brown and be very difficult to remove, at least quickly. Pyrex is safe up to about 500 or so degrees, perfectly safe to use in your outdoor oven, just keep the heat indirect, not underneath it.
A typical 33x22cm cake pan fits in the middle of a 57cm kettle, with heat on either side in charcoal baskets. I've made more than a few lasagnas that way, only in inches instead.