Definitely normal. Don’t look at the work which needs to be done, look at the space and how it will work for you. Picture yourselves in the bedrooms and the kitchen and the garden, not as it is now, a bit shabby and dingy. But how it will be when you’ve painted it, with your things in it, and knowing it’s yours and no one can sell it from underneath you or turn up and insist on inspecting it, that you can put whatever colour you like on the walls and stick things up however you like too.
And depending on what disabilities your children have, and what your income is, there may be grants available to help with the decorating and floor covering etc. www.disability-grants.org/ is quite comprehensive. But look around locally too - some places have local charities who will help by doing some of the donkey work.
Depends on your friends and family, but when we moved I arranged for a bit of respite and then had a minions assemble call - lots of people came over to help paint and assemble furniture, I ordered pizza and curry and was hugely hugely grateful.
A friend had a Pivot ! Party to sort all their awkward furniture.
Another friend does a great line in swapping cakes for DIY.
But actually last time we redecorated I found a handyman rather than a professional painter and it was £300 plus paint rather than £3000 including paint. Yes the finish is probably not as pristine as it would have been. But tbh the wheelchairs trash it anyway.
High ceilings aren’t an issue though you just need non drip ceiling paint and a long arm roller. Quite satisfying. And if you do the ceilings first then any spatters on the wall you’ll be painting over later. And once it’s done you can lie down and look up and it’s all clean and bright and there are no piles of toys or equipment cluttering it up.