In the main , for every person that replies here , you will get a different answer . What one person thinks is well off , another thinks it poverty . It is the classic " how long is a piece of string ?" .
Too many variables to answer off the cuff really .
Do you own your own home ?
Do you have experience with livestock ?
Do you 'both' really want a smallholders life ?
Can the wage earner still earn once you get a holding ?
Can the other one cope with all the work and the kids on the holding ?
I could go on forever !
If you own a reasonable house worth £300,000+ you may find a smallholding somewhere for a similar price , if you are lucky , but the variables come in again . Is the land any good ?
Can it cope with livestock ?
Depending on area , is the growing season long enough for all your veg crops ?
My reply is not intended to put you off in any way , just to say that ultimately , only you can answer the question , based on what you want out of life and your own perceptions .
Read as much as you can on tas though . The alternate view , ie without rose tinted specs , is on here , for those that want to see it anyway .
The best thing you can do though is what you have done , ask questions , and apply the answers to your situation .
Good luck anyway .