kind of a stupid question..

[The Dad Fisherman]

You should be able to pick up a Wireless card for a desktop for around $40 at staples or Comp USA. something like a netgear should work fine

[Redsoxticket]

Do you have cable going to your TV digital box ?

If yes then you can attach a 1:2 splitter.
1) Remove the cable going to the TV box
2) Attach cable to the splitter input. Note that the splittter will have two outputs.
3) attach a cable from the output of splitter to TV box.
4) attach another cable to the modem as you had configured down stairs.
5) done

or

If you have cable going to any unsed wall outlet in the house then attach the modem.

Since your remodeling it may be a good time to install those extra cables.