"Those existing hardwoods are not a color we like, and we expect to refinish them. Just wondering if I need to think about a stain that will work for ALL of these rooms when selecting for the kitchen (if they all should match)..."

Yes, they all should match. Your need to make sure to take your kitchen cabinets into consideration, if you're going to refinish the whole shebang, start with coordinating the stain with the cabinets and other fixed elements. You need some degree of contrast with the cabinets. Wall paint is easy to change, it's the fixed elements that are not.

A neutral mid-brown is easy to live with, goes with pretty much everything, and pretty hard to screw up. When you get into strong undertones in the stain, that's when the coordination problems start.

Throw into the mix of choices one where you find a wood species and tone you really like. You carry the new flooring into the dining room and foyer. New engineered flooring in wider than solid/ Starting at 7" and going to over 11. Some current popular choices include European oak in flat cut. Either rustic with small knots or prime without. That species is denser without the open grain of N. American Oak. That's why flat cut can be used to show off the wood structure more like furniture.

All the flooring matches, as does the stain, and kiss the edge to edge carpet tata as you do that.

You test the stain on the new wood, and the older you plan to refinish after it is sanded, everywhere.......on site.

Shim up the lower cabinets at install to account for the hardwood. Pecking at remodel in a now and later fashion indeed makes flooring more difficult. I'd try very hard to unify all at the same time - species and stain

I agree all wood flooring in a home should be the same. If you're lucky enough to have original solid hardwood, then continue it into the kitchen. And a medium neutral brown goes with almost everything. Try Provincial or Special Walnut.

All the same flooring and IMO when shopping for the flooring get enought to do the LR too even if not right now. . If you like the color in the other wood floor then find out what wood it is then get the new unfinished same and have it all stained the same . I agree a nice neutral medium brown is very timeless.

When selecting wood floor stain for a renovation, consistency across rooms is key, especially if they are interconnected. Ideally, the kitchen wood stain should harmonize with the dining room and adjacent areas. If you're planning to refinish existing hardwoods, consider a cohesive color scheme for the entire floor. This approach ensures a seamless transition between spaces, enhancing the overall aesthetic.

Thank you all for the helpful replies and details. this has all been very helpful. we have an estimate already for refinishing the existing hardwoods and plan to do it sometime around the kitchen timing.

The feedback here tells me to do the extra “mental calculus” to select one color for all the areas intended to be hardwoods. That also means sticking with the existing skinnier wood as well to be consistent. Provincial was already one color I was favoring, so helpful to even see that referenced above. We’ve not done a project on this scale so this helps me feel more confideant.

You can also combine stains to get the look you want. That’s what we did. Just get your flooring guy to make samples on pieces of the wood species you have. We did a blend of Nautural and All American.