Based on the rumours (and trying to see around some of the garbled reporting of them) the new M1X 14" and 16" MBP are going to be potential replacements for your ThinkPad P1 that start at $1700-$2000 and rise to infinity and beyond. If you just want an ultraportable with long battery life as a secondary machine, the base M1 Air will probably still be the appropriate choice.
Everybody is guessing at the moment - but to me the most likely scenario seems to be that the cheapest M1X 14" will replace the $1700+ Intel 13" MBP , and the M1 Air and low-end 13" MBP will hang around until the all-new M2 Air appears sometime in 2022. My guess is also that the low-end MBP won't have a reason to exist when the new Air appears.
The M1 Air should ace web browsing and MS Word. You'll have to check that the specific coding tools and libraries you need are compatible with M1 & Big Sur. Of course "some coding" is as long as a bit of string, and if you're coding software that needs 32GB of RAM and processors, 8 performance cores and 3TB of storage to run then you're obviously gonna have problems... but otherwise the M1 should eat coding and compiling for breakfast.