The front of the house requires a reliable bloomer and re-blooming hydrangea would probably serve you better in there. I do not mean ES necessarily but either one of the other reblooming series (Let's Dance, Together and Ever, etc; or perhaps Annabelle-type hydrangeas or a compact paniculata (yes, I know... no colored blooms). But I am not good with landscape questions so let's see what others have to say.

Thanks Luis!
I'm okay with having just foliage for some of the growing season, so a re-bloomer isn't essential to me. I do not want white so Annabelle is out (sorry!). I'm definitely curious if there are others out there that would serve me well besides the ones I've listed, but I'm hoping at least one of them could be a winner :)
Edited to add: Ah, I see you mean a re-bloomer would be helpful because of the "insurance" of not losing buds to frost. If I do keep the hydrangea in a container (half-barrel?) I can bring it in to avoid frost, which I hope increases my number of options.

Here is some information on a few of those:

Merritt’s Supreme resists going blue and turns purple instead
(unless your soil is REALLY acidic). Not sure about Merritt’s Beauty.

Altona – Produces a vivid blue in acid soil. Dirr reported
that it may be a problem in the blooming department sometimes. Researching the
weather on the year that had few blooms noted lows below 10 degrees nearby so
it is possible that those cold temps killed the flower buds.

Blue Danube – Has a
striking blue tone in acidic soils and is very compact, which is good for you. Blooms are similar to
Mathilda Gutges. MG here in Tx produced flowers of multiple colors in amended
soil and is about 4-5’. This reminds me that Enziandom also produces good blues
and is compact.

Recommended mophead blues by Lynn Church: Blue Prince, Enziandom, Generale Vcomtesse de Vibraye, Hamburg, Marechal Foch, Nikko Blue.

Recommended lacecap blues by Lynn Church: Blaumeise, Blue Bird, Blue Deckle, Miranda, Nightingale.

Of course, all these bloom on old wood. The advantage of rebloomers, aside from what you mentioned above, is that they tend to trigger new blooms when you prune off spent blooms. So as the original set of blooms start to change from blue to blue with pink/green, you can deadhead them and trigger brand new blooms that will maintain the blue look that you like.

Sorry to break the news, but if you are trying to achieve sizes you speak of in Zone 6, you likely won't get anyhwere close to doing it and have many flowers with anything but Nikko Blue (largest) or ES/relatives. ES's relatives include offshoots Bloomstruck, lacaps Twist n' Shout and Summer Lace, then closely followed by things like Nantucket Blue, David Ramsey, Penny Mac, Decatur Blue, etc. There are also newer plants on the market like LA Dreamin (Lindsey Anne) but it's a newer plant. Black-stemmed ES is called Enchantress. There might also be a few exceptions like Edgy Orbits (bi-color lacecap) that people have found to be on the hardy side.

If you'd rather stick with 3x3' there are many more options, such as:

- Tuff Stuff (serrata)
- Peppermint
- Peace
- Most in the Everlasting Series (Plants Nouveau)

2x2' and below you're looking at a few multi-colored standouts like:

- Pistachio (reds)
- Everlasting Revolution (blues and purples)

These I have spoken of have all been personally tested in Zone 6 over multiple seasons and have achieved these sizes and bloomed reliably. If your plants experience complete dieback yearly, you may find it hard to have a re-bloom after round #1.

springwood, really? My grandmother's house is also zone 6b. She had a hydrangea on the north corner of her house that was definitely over 4 feet tall, really quite large. Exact same state and climate as me. I have no idea what variety it was, but it had been there since I was a child. She is gone now so I can't ask, if she even knew. The house was built 30 years ago, so it definitely was not one of the more recently developed varieties...maybe it was a Nikko, but I really have no idea. All I know is it must be possible, as I've seen it! :)

It looks like the Nikko might be my best bet. I was really hoping for either the ruffles of Altona or the intensity of blue in Blue Danube. The house is pale yellow so I was excited for a deeper contrast. Before I go out and buy that Nikko (will purchase a 3-year plant as that's the largest I can easily find afaik), does anyone here think Altona or Danube could be okay? If not....it is what it is, I'm afraid :)