Went Roku years ago and never looked back. We had DSL at our old house, I think 5Mb/s, but had no problems. No 4k TV, no 55" screen though. Only one device running Roku although we never had a problem watching a movie and casual websurfing at the same time.
One nice perk of cutting the cord was that after about a year we had no idea what was hitting the movie theaters--nor what the latest and greatest TV show was. Cutting the cord cut the commercials too. On average I watch maybe an hour of TV per week. My wife watches a bit more but she has several series on DVD (remember those?) that she has had for years and that she can put on while doing cooking, sewing, whatever.
One nice perk of cutting the cord was that after about a year we had no idea what was hitting the movie theaters--nor what the latest and greatest TV show was. Cutting the cord cut the commercials too. On average I watch maybe an hour of TV per week. My wife watches a bit more but she has several series on DVD (remember those?) that she has had for years and that she can put on while doing cooking, sewing, whatever.