Partial Boil volume for 10 gal batch?

What would be the smallest partial boil I could do for a 10 gal batch without really screwing up the flavors, hop utilization, or other characteristics. I don't have that much time to brew and I don't have much space or equipment so I was curious as to using my 5 gal pot (4 gal boil volume) to make a 10 gal batch. I've started using DME and late additions if that matters, and I'm probably looking to make some simple summer type ales. I have enough fermenters, but not boiling equipment for a 10 gal batch and the budget right now is zero for add ons. Has anyone tried this, is it not recommended?

Any thoughts on this old post? I was thinking about doing the same thing in a few months. My mom has been requesting a low ABV double IPA (Oxymoron, I know) but I think she's really after a really hoppy pale ale with decent body. I think I've come up with a good potential recipe where a 4 gallon boil at 1.101 gravity would yield 10 gallons at 1.040 (and an estimate FG of 1.014). Because of the anticipate rate that this beer will be drank, I'd like to get 10 gallons out of the batch so I can give some to my parents and brothers-in-law and still have it last for awhile. Just curios what considerations I should take while making this extreme of a partial boil.

i don't think this would turn out right; maybe too light in body. i'd think the minimum would be 6 gallons, but i could be wrong. just my 1.5 cents worth (not even worth 2 cents)