I put my Citra chinook APA in my brewery at 70 degrees. Held stable for the first 3 days but my wife left the door open to the furnace. Temp spiked to 76. How much did it affect my brew ?
After three days at 70, fermentation was probably complete. I doubt the temp spike will have a great effect.
However, I think 70 is a little warm for your IPA. It depends on the yeast strain. I keep mine in the low 60s. Keep in mind that your beer temp is 5-10 degrees warmer than your ambient when fermentation is in full swing.
That's surprising its still going strong after 3 days @ that temp, I ferment @ 70 using us-05 all the time with no major issues, just depends on the yeast.