Depending on your household wiring you might want to look at a ‘HomePlug’ type solution, using powerline adapters to extend the network. How well these works depend mostly on your wiring, you can expect about 20-40Mbps through these in real world conditions which might be okay for one or two devices.
Otherwise, you can look at mesh networking. This generally involves having a seperate wifi device between a good and bad signal spot to extend the range. They used to be quite poor but the performance of these has increased dramatically.
Since moving to my new place I got one of these from BT, my provider, as although I am in a fairly small flat the signal doesn’t get beyond my lounge (concrete walls). I put an additional disk in my kitchen which helps with my wifi there (Alexa) and my front door (Ring doorbell) and it has made a world of difference.
If your provider won’t supply them or wants to charge an extortionate amount of money for them, there are 3rd party ones such as Netgear Orbi or Amazon Eero that do a similar job.