I cannot get good connection on my smart TV. It is only 75 feet away from my cable provided WIFI modem. The modem is free of obstructions. Is this too far away for quality connection?
75 feet is borderline for the average wifi router. Remember that not all routers are made equal. Some cheaper brands/models have low range, more expensive ones have better range, should tell you on the packaging. Also, you could try a wifi range extender but the downside of those is that range goes up but speed goes down.
I think you ought to consider a better router with longer range.
I have the modem that comes with my Comcast system. I was told that the reason my smart TV won't get Netflix in the bedroom is because they are only good for up to 25 feet away from the Wifi modems. Is that correct?
A 25 foot range could be correct with less capable wireless routers. The best way to test this is to move the router closer to the television if possible. Moving it only a few feet can make all the difference. A range extender is an option but as pointed out already it will affect your connection speed considerably so probably not ideal.
I myself use an Ethernet Over Power (EOP) solution for this very reason. I get decent enough speed that I can send Bluray quality information through my homes electrical wiring to any room in the house without issue. I currently have three separate rooms in the house accessing my router at decent speeds.
Something like this would be ideal:
http://m.newegg.com/Product/index?i...
You can get these that will give you 500 and even 600 Mbps speeds if you need it.