Or... is there is another way to keep recording through my death and quicksave reload? 

Some engine ports support continuous recording. QuakeSpasm and Fitzquake Mark V do, and I believe DirectQ as well. Not sure about Darkplaces or Requiem. Additionally, Mark V also supports playback of 'broken' demos - those that were recorded in ports without corresponding support.

In my view, the safest thing to do is to make multiple demos using the tick where you resume a recording from a savegame:
When you die, stop the current recording and disconnect. Then start a new demo recording in the console with a different filename but without typing the map name. Then just quickload and continue. 

Bengt Jardrup's Convdem tool can merge multiple demo files, but only if they are protocol 15 or 10002. Sadly, it does not work with protocol 666 which FQ, QS and DQ default to. 

How would that contiuous recording work in quakespasm. I tried to quickload while recording but that stopped the recording.

Also I have read about the trick with stop, disconnect, record, quickload several times but how is that different from just quickloading and recording a new demo? 

The s/d/r/q trick is what works with every Quake client and protocol - maximum compatibility.

The current version of QS can start recording at any time during the game. But quickloading always disconnects the server which stops the recording. AFAIK, in QS continuous recording only works for automatic restarting after dying or progressing to the next level.

Doing a bit of manual work, you're on the safe side if you want to ensure your demo(s) can be watched without trouble. 

You might try this.

Demo 1: Open in hex editor. At end of file locate a 02 (sv disconnect = 2), which will terminate demo playback in standard Quake and most engines, and change the 2 to 1 (svc_nop = no operation).

Use a utility to binary join the 2 files together.

On Windows supposedly: copy /b demo1.dem + demo2.dem demo1_plus_demo2.dem

I suspect the new demo1_plus_demo2.dem will play just fine because the next message will be the play of a new demo sequence. 

you'd also need to strip the number+newline from the start of the second-onwards demos.
if there's junk after that '2' byte, like the text 'end of demo' or other junk like that, you'll need to change those bytes to nops too. 

I got it to play a demo after the end of another. Yay, so that worked. qspasm crashed then but it might be just the files I used/destroyed.

I'll try to automate this.

I've found a link

http://www.gamers.org/dEngine/quake/Qdem/dem-1.0.2.html 

Record to avi/mpeg/etc instead of dem?