A couple of random thoughts.

1) "Stoves" are hugely more efficient than "fireplaces". So, if gas turns out to be a nonstarter for some reason, consider replacing your existing wood fireplace with a wood stove. Vermont Castings (no affiliation) has some very efficient ones. I've used their wood stoves as well and found them to be great units.

1a) Getting the smallest, high efficiency wood stove you can, potentially will allow you to stretch your wood supplies.

2) If you switch to gas, or if you plan on improvising heating in some way, get some carbon monoxide alarms. You can get combo fire alarm carbon monoxide alarms to replace existing fire alarms, as well as stand along units. You can also get combo gas / carbon monoxide detectors.

-john