The best outcome would be that we (the U.S.) gets sucked into an extremely costly and protracted new Vietnam in Venezuela and our 'allies' in the West (and our bitches in South America) abandon us to our own devices.
I say this because being tied up there in Venezuela in probably the only way we are not forced by the Zionist masters of our so-called leaders in Washington into 'doing' more and more countries in the Middle East and Former Soviet Union. And things over there could easily go nuclear.
That is highly unlikely, they could form a few guerrilla groups and produce some violence, but nothing even remotely looking like a "war". Maduro's Venezuela doesn't compare to the previous charismatic Chavez. The amount of people willing to give their lives to defend Maduro's regime is practically zero, despite state media propaganda. You might be fooled into thinking he is the same because he was appointed by the former, but he is not...
Any sort of military resistance would disappear within hours, and most likely you will see en-mass surrender. This is because the Venezuelan military know more than anyone else how bad their situation is with what little equipment and weapons they have in working condition. From a military perspective, the only sensible answer is surrender. The Venezuelan military can deal with drug traffickers or smugglers in border land, sea and air patrol, but they are in no condition to engage with any other military force of any country, including Colombia or Brazil.
Suffice to say that the US dealings with Colombia have been far more longer and complicated, than anything that could possibly come out from Venezuela.
But if you mean it could be used politically as an excuse for "we are too busy here to go there", well i don't know, USA has enough military capacity to deal in many fronts at the same time. Not to mention this is the UAVs/drone warfare era, where you don't even need to risk human pilots anymore and can field plenty of remote controlled units 24/7 over vast areas. Proximity is also so ridiculously close they could launch from home, and we do technically share a border with the USA in Puerto Rico... A civilian jetliner can do the trip from continental America in under 4 hours, and a civilian cargo ship under 4 days.
This is the typical scenario where a politician would say "surrender is not an option" but the military understands that "surrender is the only option".
The best outcome for Venezuelans, right now, is to show such a display of muscle from the international community to make the regime surrender without any resistance, and this is what i think will happen.
Looking the other way and letting the regime continue is only going to continue the grief and deaths, and mass exodus...