Congratulations on your winning ticket.
Perhaps your winnings will be paid in one lump sum this year. Your tax bracket will, of course, be the maximum, and there will probably be tax withheld from your winnings. You will file your return
and you will owe whatever the total tax bill will be.
Whether or not you are married will have little impact on your total tax bill. The bracket will not be changed, whether or not your spouse has income
of their own.
Perhaps, on the other hand, your winnings will be paid over a number of years. For estimating purposes let's assume 20 years, or $37,500 annually. The only difference in your tax situation (Scenario 1: marry this year; Scenario 2: marry next year) would be for THIS year's taxes on $37,500 since either way you would be married next year. The difference in your taxes this year on the first year's annual payment would be relatively minimal whether you are married or single.
From this I think whether your payout is lump sum or annual, it really doesn't matter that much whether you marry this year or next year.
Conclusion: don't make your marital decision (or, in general, most business decisions!) based on tax considerations. Make the right decision for the most important and relevant reasons.
Hope these thoughts help.