hmm. USB to wifi and back to usb? That's going to be slower still. Ok for simple updates but archiving programs, loading them on your laptop for watching your programs on the road, etc is going to be slower.
Do you have cable, ota (over the air) or satellite?
If the laptop had built-in wifi and that failed after working fine for a long time (versus infant mortality), then there is a possibility that if that failure was stress related (dropping, surges, etc), that other parts of the laptop may also fail soon. It may also work fine for years to come.
I assume since you have a cell modem that you are on the road alot so using a tv to usb interface to record your programs to your laptop is not going to work for your situation. You probably prefer a stand alone box that can manage things while you are away and present them as little digital gifts when you get home.
Usually, the program listing can be downloaded for the next 2 weeks. As long as you are not away longer than that, it should grab all your programs on time. Although, it is better to update more often just in case the lineup is changed at the last minute.
To bad we can't yet get all of our tv programs via the internet. Pay for what you watch, ignore the rest. The hardware would be a bit more straightforward.
If your typical use is just 1 or 2 programs that don't change much each week, then a simple timer-based dvr should be fine. But if you watch more than that and the programs sometimes change and especially if you have satellite or digital cable, you can get a program based dvr usually for pretty cheap with your service. For example, direct tv had a promo going where you could get a tivo for $50 and the program data is $4.95/month (regulary $12.95/mo). I don't know what the current specials are.
Peter