I have wireless intervalometer.. got it from ebay for ~$30.
It consists of two units, one (transmitter) looks like "normal" intervalometer (also can be used in usual way), another part (with receiver) is attached to camera.
Here it is:
https://www.ebay.com.au/itm/16364295...frcectupt=true
There are also IR remote controllers for Canon, but camera has sensor on the front.. so hard to use if camera is pointing away .
https://www.ebay.com.au/itm/30372091...0AAOSwJJRfgWcP