This SMC router at newegg claims 1155 feet.
I have an older SMC 802.11b router and the distance is quite good. Haven't measured it, but my guess is I can get at least 500 feet at 10Mbits/sec -- and that's with a wood wall between, and a lame (free) gigafast ethernet adapter on a laptop.
Figure you've got at least 2 walls between you, so the router may drop down to 1Mbits/sec -- but that's ok, since your broadband won't be much more.
I'd definately say YES to your question; but go with a router that at least claims some distance -- like an SMC.
If the farther computer is not a laptop (even if it is... but it's not very convenient), then in the worst case you can get a wireless card with an external antenna. Powered antennas can be had for < $50.