Just some quick thoughts.... I haven't read the other replies, so forgive me if I am repeating.
We stayed off-site twice when the kids were smaller. Both times at a Homewood Suites (no longer a HWS property

). We weren't worried about missing out on EMH because the kids were too little to stay up for all hours. I checked and rechecked and called and recalled and negotiated repeatedly to get a price that I was happy with (remember that this was several years ago AND off-season).
Because we had a suite it had a small kitchenette, plus the hotel offered free breakfasts and free "manager's reception" in the afternoon. We ate breakfast at the hotel EVERY DAY except when we had breakfast reservations in the park (once each trip). We also took advantage of the afternoon reception on our "off park" day and considered it dinner. And we had dinner in our hotel room several evenings of each trip (it was January and the parks closed fairly early, plus we didn't want to keep the kiddos up all hours). We made one quick grocery stop on our arrival day PLUS I had shipped down a box of non-perishables (mostly for DS, since he has food allergies). Believe me when I tell you that it was NOTHING fancy or special... some dinners were PB&J and an apple.... a few evenings the kids were too tired to eat and were bathed and ready to sleep by 8 or 9 pm! I believe once or twice we splurged on a delivery pizza or DH drove to a nearby Subway while I got the kids ready for bed.
We did bring some snacks to the parks every day (juice boxes, granola bars), but ate lunch and sometimes heavy snacks at counter service stations throughout the parks.
It saved us a TON of time and TONS of money! We weren't wasting valuable park time in restaurants or eating. When we arrived in the morning for rope drop, we were ready to go! In fact, I've often felt that one of the BIGGEST time wasters of our first trip was our lunch at Rainforest Cafe. We had ONE DAY scheduled for AK (we had never been there before) and we ended up spending over an hour of that day at a mediocre lunch. Never again.
Like I said, that was many years ago and the kids are older now, but I STILL pack/bring along breakfast and snacks for our trips. DD and I went down for 4 days in 2013 and 2011 and I packed breakfast for every day in my luggage. Instant coffee/cocoa/tea, instant oatmeal or cream of wheat, individual fruit cups, and homemade muffins (frozen and packed at the last minute). I also brought along an electric kettle (since we stayed value and there was no coffee pot) and a few plastic spoons and paper bowls and napkins. We have a healthy, fast, cheap breakfast every morning before heading out for a LOOOONG day in the parks. We DO stay on-site now to make the most of EMH, since the kids are older and can go, go, go!
Anyhow.... I would DEFINITELY take off-site/no dining plan Disney over NO Disney! (I'm not a dining plan fan and wouldn't ever consider paying the money for it.) Do what it takes to make it a memorable AFFORDABLE trip! Good luck........................P