Aging 5 gallons of beer in 6.5 gallon secondary?

I'm planning on brewing a belgian dark strong ale, and probably bulk aging it for a month or two after the initial 3 week primary. Problem is, I only have 6.5 gallon primary fermenters, and I don't usually use a secondary for anything. I guess I have 4 options here, which one is the best?

1. Leave it in the primary for the entire time.

2. Add it to a 6.5 gal fermenter and purge the headspace with CO2.

3. Add to 6.5 gal fermenter and at the same time add some sugar (that was in the recipe anyway) to feed the yeast to create CO2 in the headspace.

4. Don't secondary, and just age in the bottles after primary fermentation is over.

I'm leaning towards option 1, just because it's the easiest and I don't foresee any issues with doing this one. The OG is 1.087, so would it benefit from an even longer primary than I usually do?

When I bulk age I use option #2, after 3-4 weeks in the primary .

hamiltont said:

When I bulk age I use option #2, after 3-4 weeks in the primary .

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I agree. For a beer you want to age a bit, moving it to the carboy and purging the headspace with co2 would be just the ticket.

Number 2 is the ticket, but honestly, I doubt you need to purge the headspace. It's still going to be generating a little bit of CO2 and that will lay like a protective layer on the top of your beer. Won't hurt to purge; but not really necessary IMHO.

1)Lots of brewers on this site use buckets only.

2) Im with knightbeer39 it will make its own layer even if its only a 1/2 inch. CO2 is heavier than air and will push the air out

3)

4)