Hello all-

I'm hoping everyone can help me with a little truck buying advice. In 2019 I purchased a new F-150 3.5 from a dealer at their zero percent interest rate. It's been a great truck for 3 years, but the 5.5 bed is too small for my daily activities, (hauling travel trailer/four wheelers/hunting and fishing). So I am looking to move up to an F-250/350, (trailer weighs 5800lbs roughly). The only problem is I'm 5k in negative equity on my F-150, and the prices on new and used Super Duty's are bonkers.

So, I've come up with some options:
1.) Sell truck to dealer, and pay 5k to clear negative equity. Buy 96 Powerstroke with 180k miles, (clean), for 20k.
2.) Keep truck and deal with small bed, but continue to have 0% interest rate. This option scares me due to the value of my truck dropping with continued use.
3.) Sell truck to dealer, roll negative equity into new truck. Lose 0% interest rate. This is my least favorite option.
4.) Sell privately. I've tried this for months and have not had anywhere close to success.

I use the truck primarily on the weekends to haul the trailer/atv for hunting purposes. I will probably put 15k miles per year on it. I live in Montana, so reliability with the winter is a big concern.

What should I do?