If you need that money for a payment 3 1/2 months away, then you need to be extremely risk averse.
Maybe even to the point that you may want to spread that $1mil to several banks to stay under the FDIC limits of $250k/account.
You will not get great return, but you will be sure to have it when you want it such a short time away.
money.stackexchange.com/users/51412/R. Hamilton
In addition to R.Hamilton's answer (upvoted), I would add that there is some not insignificant risk at the moment of financial crisis #2 due to the demand and supply shocks, (covid 19 + oil market drops ), overstretched corporate borrowing, and central banks having run out of ammo trying to keep 2007 on ice.
I think it would be very wise to split the money into separate banks for insurance coverage.
Maybe look into short term term-deposits.
EDIT: Update.
Since the time of posting this answer I would change the opening "not insignificant risk" to "highly probable", if not actually declaring that we are now in fin.crisis#2, opening rounds.
money.stackexchange.com/users/91156/Frank
Unless you want take a more significant risk, that's probably anout the best you can do.
Investing it into the market - bonds or ETFs or even shares - would give you a chance to earn a lot on it, but also to lose a lot on it.
With a short time horizon like this, you would not be able to recover losses.
If you had ten years, the recommendation would be to buy some ETFs and make 4-10% in average.
For not even four months - take the 1.7%.
money.stackexchange.com/users/35405/Aganju
Possibly, invest the funds long-term and re-finance the land debt from a position of better credit standing.
Also, close to 50% of the funds in a brokerage account can be taken out of the account on margin and institutional margin rates can be found.
Then an interest-only loan can be developed such that simply future performance of the investment possibly pays off the loan.
I called that situation an interest-only loan because the percentage of margin deposit must be maintained while the minimum financial drain is the margin interest.
money.stackexchange.com/users/80802/S Spring
Of course, I would always consult a fiduciary investment advisor.
I would imagine my investment advisor would recommend investing the money long-term in a diversified allocation portfolio, possible refinance the land debt (when interest rates drop lower, hopefully soon) and service the land debt from the growth/income from the invested money.
money.stackexchange.com/users/13935/Arluin
We have 1 million dollars from the sale of a farm, which we want to use to pay down land debt.  But we can't make a payment until the anniversary date of July 5.  Right now it is in an interest bearing checking account earning 1.7 %.
What to do with $1,000,000.00 for 3&1/2 months?
money.stackexchange.com
<investing><interest>
money.stackexchange.com/questions/121672
money.stackexchange.com/users/None/
Split the money into different banks for insurance coverage. You could look at short-term deposits. I think it would be wise to split the money into separate banks for insurance. Short term term-deposits might be a good idea. Investing it into the market - bonds or ETFs or even shares - would give you a chance to earn a lot, but also the potential to lose a lot.
I think it would be wise to split the money into separate banks for insurance. Short term term-deposits might be a good idea. Investing it into the market - bonds or ETFs or even shares - would give you a chance to earn a lot, but also the potential to lose a lot.