You are welcome.
In my particular case up until relatively recently I had got into the habit of staying in the premier inn terminal 2&3 on bath road (ring road around heathrow) to get the first sas flight to oslo that leaves at 7am.
There is a bus stop 'oxford avenue' right outside the hotel, however, even at 04:30am although the transport for london website indicated regular buses passing (and quite a few did) there was 2-3 of number 105 that were simply too full taking airport workers into heathrow central.
I was there waiting 40 minutes in the end and was only able to use the 111.
If you had large amounts of luggage, an impractical route anyway.
There are hotel hoppa buses which service the hotels around heathrow, but more expensive and less frequent.
Ubers and taxis as well obviously.

It will really depend on peoples circumstances and where they are starting from.
E.g. the heathrow express train will get you in from paddington but takes 15 mins and less frequent in the morning.

The hilton garden inn terminals 2&3 is walking distance to terminal 2, but post pandemic is too expensive for my taste.
There is also the aerotel in terminal 3 I think, convenient, but expensive shoe boxes...

If you have a slightly later start another option would be the thistle (somewhat tired) at terminal 5 and then take the austin powers style monorail to terminal 5 and then connect to the free train for t2.
Does have the advantage of hotel+parking packages, although I would imagine many other hotels will offer this.

Hope you have a good trip!