@Craig *********
Sorry I can’t say for sure. Flying may well be an issue as the airline may have a policy of not allowing you to board if you don’t have 6 months left. Generally Laos has the most lenient land border controls. Whether they’d give you issues is just something I can’t say for sure. It’s up to the immigration officer you’d hand your passport to.
Technically your old passport becomes null and void once you apply for a new one, however when applying for a new one here they don’t take the old passport or “clip” it on application so in theory it should work fine.