I don't think barrel aging under 30 gallons is ideal (this batch will probably be around 13 gallons pressed) but we should be ok with a 15 gallon and a top up wine, both I can acquire.
If you don't have a small neutral or near neutral barrel, going with glass or stainless steel is a better choice. Two of my three 55 liter barrels are neutral (manufactured in 2010), so long term aging is not a problem. I was given the third last fall -- it's 2 yo but had wine in it for ~13 months, so I'm watching it for over-oaking.
Carboy aging is very home brew, I should have 2x 6 gallons around somewhere, I just don't like glass much. I could also just age in stainless and call it a carboy since stainless is similar to glass in the resulting wine.
For most home winemakers, cost and storage are significant issues. Glass carboys are the solution for both problem.
Stainless is essentially the same result as glass, and you can store the wine as a single unit, instead of having it divided between multiple carboys. Many moons ago I had a pair of 13 gallon carboys, and those were heavy even when empty.
Do you have oxygenation issues openly moving it this much?
Following up on Brant's comment, I was originally taught to rack wine every 3 months. I did that for decades, but later questioned it, and in recent years researched many things. After reading about sur lie and bâtonnage, I greatly reduced my racking schedule, and currently rack only when the wine or the situation requires it. Typically for my barrel wines I press, rack 2 or 3 weeks later into a barrel, and rack again just prior to bottling. Situations for carboy wines may add another 1 to 2 rackings, but I keep the number as low as possible.
As an answer to your question, as far as I know, I have no significant O2 problems. Oxidation is not a rapid process -- it's a factor of wine volume vs headspace volume vs time. I rack efficiently (not rushed), and given that most of my production is currently in batches of more than 60 liters, vacuum doesn't work for me so I have not invested in it. Plus I add K-meta on schedule to address oxidation.