... so I don't foresee needing to spend any large amounts for repairs anytime soon.
Don't count on it!
I'll share what I do.
For expenses (as W2R puts it, our salary): I keep 6-12 months expenses in a MMF. I have a lot of the bond portion of my portfolio in a Short Term Investment Grade Bond fund (VFSTX), which is safe enough for me.
My AA is 60 stock 40% bond+cash.
For maintenance / large expenses: my budget includes the average that we spent for this category over the past years. My expectation is that it will be sufficient for most years. If I have to spend a lot more, I'll take it from my emergency fund.
For a emergency/slush fund, I carved out about 5% of my portfolio before
calculating my initial SWR. This money is part of my portfolio (and invested per my AA), but not used in calculating my annual withdrawal. I use (roughly) the 4%/95% rule from Bob Clyatt.
This emergency fund will be used to supplement our maintenance/big expense budget and also to supplement annual withdrawal for those years when 4% of the portfolio is too little to live on. I'll replenish it in good years.
Our situation is Semi-ER. Come end of this month and we'll both be employment-free again!