Hi expat
The logistics don't sound like a problem, and tbh I have not struggled with homework/practice etc ...
I have no gaelic and neither does dh. The school are very very good at providing phonics training, tapes with the reading books so I can check pronounciation, a homework guide with all the key words in it, and it is amazing how much you pick up as you go along.
Dd1 started in a small Gaelic unit and they also provided all this - as well as being on the end of the phone if we wanted, and letting us drop in any time. She then moved to the big school in Glasgow and has flourished there too.
I love bilingual education - the benefits are huge. My kids also both have children with special needs in their classes, and they seem to be doing well, but it would depend on your dd1's needs. But NT kids with bilingualism do better in Maths, other foreign languages and reasoning right up to secondary school, and they think beyond though the research hasnt been done yet.
Dd1 didn't have any gaelic going in to school and had no opportunity to practice, but did fine and even won a local Mod gold medal in her p1 year. They talk a bit together now, but not a lot. One of the best things has been meeting other gaelic speaking families - ds goes to his best friend's house where they all are native speakers adn he just chats away in gaelic to his friend's mum not bother.
The cultural side is good too - the instruments on offer, the singing - both schools we have experience of did a lot of public performance, which meant that my dd1 at age 6 was able to stand up in front of literally half the island and recite a poem.
I would highly recommend it. Also, dd1 is now at the stage of learning English as well in school and is already almost where her English-only friends are at. Not quite, but I am amazed at the speed she has picked up reading and writing in the 2nd language.
Just get in touch if you want to know any more!