You might weld an oversize bung on the oil pan before you drill the hole, then bush the bung down to the sender thread. That way you weld on a pan full of oil, away from the oxy in the crankcase, then drain the pan, drill the hole, remove the shavings with the mag, and you're done.

Or, put the sender in a wet well on the cooler feed line from the filter adapter, near the adapter. I found that my oil temp sender was excessively cooled by air circulation and had to insulate it with rock wool and a tape wrap to get reliable readings...

Not responsible for advice not taken...