You may want to use short-term funds for the money you are spending in the next few years. However, RMDs are not money you are spending; they are money you are required by the IRS to move from one account to another. If you have an RMD that is more than you need to spend, you can take the RMD out of the TIPS fund in your IRA and put the same money in the TIPS fund in your taxable account, or in I-Bonds.
Another good use of excess RMDs is to pay the tax on converting part of the IRA to a Roth, reducing future RMDs. (You should only do this if it won't move you up a tax bracket; there is no point in paying 25% tax on the conversion to avoid paying 15% tax on a later withdrawal.)