You would have to drop a reasonable amount of MMR to be a candidate for demotion. One way to find out is to see you, your team's and enemy's MMR. If your playing with silver 4-5 players, you are definitely close to demotion. To get an estimate of what your hidden MMR is, check out op.gg
If your MMR is 3,4 and in extreme cases 5 divisions below your current Rank, that's a red sign. I would take is easy. Since Gold players do not decay, I would stop playing because the season ends in less than a month. In about 20 days, Season 7 will finish and ranked rewards will be handed out. You'll receive Victorious Graves and a chroma, with a gold loading screen border if you end the season at gold.