Reply minus reference link:
91.265 & 91.280
give some guidance,
Bottom line:
Unless you have enough range to make it back to the US, you will end up in the water.
Which means, good weather needs to be observed and forecast.
AND, you need to bring a raft and be prepared to get wet.
Realistically, You should plan on arriving at TXKF with two hours of fuel, that is enough time to clear enough runway or taxi way to get in. I would consider 2000' and five miles as an absolute minimum weather forecast for making the trip over (or back