Hi, sorry I'm a little bit late to all this. I spent ages researching into this. The trouble is it's really difficult to get a decent camera which doubles as a webcam for cheap.
I've opted for what I think is a good compromise, although some could argue the setup is a little over the top. The results however speak for themselves.
I have a similar issue with the webcam needing to be in the window at the opposite end of the house. I looked into numerous solutions - IP cams, even an IP inline server for webcams.
In the end to get the quality of image, I ended up using an old netbook (£40 eBay) connected to a Canon A40 camera (old but great sensor £8 eBay) and using a piece of software called PSremote (needs to be a compatible camera). This software allows full control of my camera and has a timelapse function so I can set intervals that the camera will operate.
The camera provides a better solution than any sub £100 webcam could've (non IP) and the netbook provides the platform to connect to the internet and upload photo's. The only downside is the running costs are around £3-4 a month.
I then have a piece of software called Fling FTP which uploads the images from the destination folder.
If in doubt, take a look for yourselves:
Some of the other photo's can be found on the twitter feed here: twitter.com/bovicam