Staying Out of UK query

Hello gurus

i and my son holds a british nationality but my wife is on flr fp which is valid until end of 2020,

situation is we are planning to stay back home for longer as due to i got a project here and wife also needs some times to clear her professional exams

now my understanding is i and my son are free from any time limit to stay out f UK and hope so this wouldn't impact on our status? but for my wife i know she has to start from scratch her time in UK when we move back to UK again.

Now question is what about the validity of her visa? as her visa runs out in end of 2020 and we are planning to move back to uk before her visa runs out. will the UKVI immigration will allow her to enter in UK again with her valid brp because she will be out of UK almost 15 months

thanks

any advice please ?

Sure they will allow her to enter, as she has valid visa. FLR doesn't limit time out of the UK. However, it may affect getting ILR or citizenship in future due to set limit of absence.
You as British citizen is absolutely free to be out of country for any time.

Thanks for reply

regards