I am one that ALWAYS advocates hard-wired networks - in fact when my clients want Wireless, I tell them to avoid it unless it's the absolute only option.
And I am in one of those situations where Wireless is the only good option. I've been in this home four years and I've readdressed it over and over again; house has no attic (Vaulted Ceilings) to run wires through. As an avid Astronomer I spend a lot of nights out on the back porch with my telescope and the PC that I put together specifcallally to use with the 'scope. And that's where I need the LAN connection.
I put the computer together with a Wireless PCI card in it, praying that it would find the signal from inside the house. We never used it, but the router that came with our DSL connection had the wireless ability already in it, even though the network in each room is hard wired.
The PC outside only got erratic and rare good signal from the wireless portal, so I got a Wireless Extender for it. Same deal, but with a bit better reception than before. The computer out at the scope has Internet access so I can do software updates but that's about it. The bandwidth is so low that I can't share files or use Remote Desktop from in here, which is what I need.
I swapped out the PCI NIC in the computer outside, for one that's the same brand as the extender. No change. I moved the Wireless Extender to a bookcase that is literally right inside the door to the porch, only three feet from the computer out there. Still, poor reception.
Perhaps the outside stucco wall is too thick for good reception? Would Wireless-N be any better than 802.11-G is now?
Again, with the way this home is configured, Wireless to the back porch is the only option...other than running the Cat5-e cable along the baseboards and under rugs where it would have to go over a hardwood floor.
Ok for starters how much bandwidth do you need 23 mbps is usually max if your using a WDS repeater than it's 12 mbps (I really don't know how your extender works I assume WDS repeater). I don't mean to badmouth DSL but usually they give your a cheap low range gateway. I can't say whether this is enough to get through the stucco but there is a couple ways I might approach this. WDS repeating is a pain in the butt for two reasons first you half your bandwidth every time you jump it second you have to use WEP encryption which can be broken in 3 minutes. There are two settups I know that support WDS with WPA encryption.
If I wanted a cookie cutter solution I would buy 2-3 aiport expresses. I would run as far as I could with wired to the first one then keep hooping the signal till I reached when I needed to be. They are a pain to configure but work great. I use them to get 12 mbps anywhere in my basement with two of them one next to my router and one to relay the signal with 3 you'd probably be at 6 mbps. They have WPA2 encryption and double as an itunes only sound card that can sync sound together with each unit. Run you $80 unit new $65 on ebay. The main downside is directional antenna is not an option with these guys since it is internal.
A cheaper but more involved approach is to get a dd-wrt compatible router such as a WHR-HP-G54 (might be better routers now but back when I did it this was the range champion) then hack it thus voiding your warranty. Then you get the option of beefier directional antenna as well as linking multiple units with WDS or increasing the transmit power (be careful it's just like overclocking a CPU you can go too far). Run you $60 a router but definitely the maximum range solution I know. I heard a guy push his wireless two miles with this thing and a huge after market antenna to his friends house with the same unit. Run you $60 unit and however as much as your want to spend with antennas.
Draft n does not support WDS so I have yet to see how it can be repeated but before you go nuts with any of these ideas try slapping a directional antenna on your extender or router. You could also try changing wireless channels might be worth a shot if you have any interference. Hope this helps