Help with blending and aging

If the airlock is good and the air space was really well purged, then I would say it is safe, but remember that if you are purging 2 cu.ft. of space, putting 2 cu.ft of CO2 in will not purge it. That only cuts the O2 in half as it mixes while it purges. To get it down to the level you would have in a well topped carboy, you might need to purge with 20 to 30 cu.ft. of CO2.

As far as your ideas on blending, sounds like you have a plan. Do your 60:40 blend then fill your carboys properly. Use 1 gal carboys for what does not go in the 5 gal one. Also, remember, you do not have to age all of it. Go ahead and bottle some and age it a few months in bottle while the rest is bulk aging. That way you will have some "young" wine to try while you watch the rest age. Watching wine age is the only thing I can think of that is more boring than watching pain dry. But it can be more interesting if you can sip on some as you watch in and dream of the finished product. It also gives you comparison points.

Ray