First, let me start by saying that, similar to you, I would never vote for Trump, didn’t and won’t vote for Biden, and am also in a state that always goes one way.

Having said all that, some things about Trump’s prior actions and statements make me believe that, if the war hasn’t ended by the time of the election, he would be much more likely to end the war much sooner than Biden.

Why do I say this? First, like @HarryLime said, Biden is completely bound to this war, so he’s likely to drag it out as long as possible and try to maintain the illusion that Russia is losing. I suppose that there’s some chance that he cuts his losses after the election.

Second, I think Trump has demonstrated multiple times that he’s not into war. As far as I know, he did not start any new wars or invasions while he was in office, and in fact ended a couple of them. He withdrew from Syria and initiated the process of withdrawing from Afghanistan. On Syria, he said that there was nothing there for the US aside from “sand and death”.

On Ukraine, he has specifically stated that he would end the war within 24 hours. Regardless of how ridiculous that sounds, he elaborated on what he would say to both Zelensky and Putin, and you can just tell that he doesn’t like this war either.

Most of his statements about most wars that we’ve been involved in seem to indicate that he instinctively dislikes war and all its negative impacts. Whether he would actually be able to end it or not is another question, considering what @footfaults mentioned about the generals sabotaging his efforts to leave Afghanistan.

Finally, here’s an analysis from the BBC on how a Trump presidency might change the Ukraine war.

Edit: another factor is that remember that Biden pretty much loaded his entire national security and foreign policy apparatus with neocons. In contrast, Trump had maybe a couple, with a prominent example being John Bolton, who was like a cartoon neocon. He seemed to be used more for barking than for biting. Here’s what seems like a good article about this. I only skimmed it, but this caught my eye:

Far from the textbook ideal of National Security Advisor as an honest broker, Bolton acted as a policy advocate. His strong convictions and history as an arch-neoconservative who believes in America’s role to police the world and engage in military action to effect regime change in states perceived as a threat has been well-documented. A proponent of the “axis of evil” view of the world, he advocated for the invasion of Iraq in 2003, as well forceful regime change in Iran and North Korea.

However, such war-happiness has run antithetical to Trump’s apparent view of the scope and purpose of US foreign policy. Trump’s proclivity to transactionalism and dismissal of the notion that the US is a force for good involved in a Manichean struggle against evil. Trump has been unequivocal in the view that acting as a global policeman has been detrimental for the state coffers and has given allies and partners a free ride. While Trump has done nothing to reduce US military spending – he has actually increased it – his threshold for the use of force has been much higher than Bolton’s (albeit less consistent, as seen in the case of Syria in 2017 and 2018, in response to Bashar al-Assad’s use of chemical weapons against civilians). It should be little wonder, then, that Trump remained resistant to Bolton’s sabre-rattling.