Similar situation here (older house, ranch style, super long in one direction). Even with a new powerful router, the signal at either end of the house was horrible. The router is in my office which is more or less centrally located. I invested in the 3-pack Google Mesh. Here’s what I did (translated to your house) and I now get super fast speed everywhere.
Put the router in bridge mode so it’s strictly acting as a modem. No need for two networks.
Attach one of the Google units directly to the router with an ethernet cable (this would be the one in your foyer.
Put one of the Google units downstairs in your basement to provide wi-fi down there.
Put one above the foyer positioned half-way between the foyer unit and your office.
The 3-pack lists currently for $199 MSRP, but you might be able to get a better deal by shopping around. The nice thing is that you can add additional units if necessary. One advantage to the Google system is that its back-channel (the way the units talk to each other) runs on a different frequency than your wi-fi and doesn’t suck up bandwidth. Also, every unit has an ethernet in AND out. So if something in the basement needs to be hardwired (like a printer), you can.
Mesh systems are great. I have one and my WiFi issues disappeared.
But, they tend to be expensive.
Extenders/repeaters are a lot less expensive but I’ve never seen them work very well. Also, a WiFi extender cuts your bandwidth in half. Generally, this is not something you will notice but it happens and might be an issue.
If you (general “you”) can take the initial cost hit of a mesh network I think they are worth the investment. Once in place you pretty much never think about your WiFi again. (NOTE: I am not sure how well they work going up/down different floors but work great on the same floor.)
So I went Googled ‘mesh network’ to see what the price range would be.
The first hit was from Best Buy for $99.99. Turns out that it was a ‘mesh router’, which is just one piece of equipment.
I’m assuming this would be the ‘core’ of a mesh network to which other nodes could be added, but to create a true mesh network, one would certainly have to include more equipment. Am I correct?
A mesh network consists of at least three routers. So, $100 x 3 = $300 for starters. That’s the whole “mesh” part. There are several routers talking to each other and making a signal mesh across your home. 1 - 2 routers is not a mesh. You need at least three.
Then you can buy individual routers for $99 each if you need more (4, 5, 6 and so on).
It’s been a while since I priced this stuff but I’d expect $250+ for any decent mesh setup out of the gate.
That’s what I have. Works great.* Seems a good price.
I also had Eero which worked well but one overheated on me for no reason and died (no idea why) so I got Google’s system which has worked well (and by that I mean I set it up and have never thought about it again).
*My one issue with my Google WiFi Mesh was operating it with 2.4Ghz products. It has a 2.4Ghz band but when I setup my robot vacuum that only worked at 2.4Ghz there was no clean way to set it up. I called Google and they had me walk my robot down the hall until I lost the 5Ghz signal and defaulted to the 2.4Ghz signal on my phone and could connect to the robot. It worked but that was not good design from Google. There are LOADS of things that only work on 2.4Ghz. That was two years ago…perhaps they have fixed it…I dunno. Google’s router does 2.4 Ghz…just gave me a little trouble.